The correct answers are B. Public and D. Embedded. These are two of the dataset types that SAP Analytics Cloud supports, according to the SAP Help Portal1. A public dataset is a standalone dataset that is stored in SAP Analytics Cloud and can be found in a folder location on the Files page1. An embedded dataset is a dataset that is saved within a story and does not appear in the Files list1. You can convert an embedded dataset to a public one if you want others to be able to use it1.
The other options,
A) Import and C) Live, are not dataset types, but data source types. You can import data from a file or other data source to create a dataset or a model2. You can also use live data from a source system to create a model, but not a dataset2.
1: About Datasets and Dataset Types | SAP Help Portal 3 2: Choose Between Datasets and Models | SAP Help Portal

The Optimized Design Experience is a new design option for creating stories in SAP Analytics Cloud. It offers several usability improvements and performance enhancements compared to the Classic Design Experience. However, it also has some limitations and differences, such as the unavailability of some elements that are present in the Classic Design Experience1.
The following filter options are supported in the Optimized Design Experience:
Widget: This option allows you to apply filters to a specific widget, such as a chart, table, or map, that are based on the same model. You can use the Filter area in the Builder pane to pre-filter the data that the widget displays2.
Story: This option allows you to apply filters to all widgets in a story that are based on the same model. You can use the Story Filters tool in the Tools section to select dimensions or measures that you want to filter by2.
Input Control: This option allows you to add interactive filters to a story page that allow the story viewers to filter data, compare figures, and explore relationships directly from the page. You can use the Input Controls tool in the Tools section to select dimensions or measures that you want to use as input controls3.
The following filter options are not supported in the Optimized Design Experience:
Controls: This option is not a valid filter option in SAP Analytics Cloud. It may refer to input controls, which are supported, or chart controls, which are not supported. Chart controls are buttons that allow you to change the chart type, switch between absolute and relative values, or drill up and down in a hierarchy. Chart controls are available only in the Classic Design Experience4.
Section: This option is not a filter option, but a way of organizing a story into different parts based on a dimension. A section creates a separate page for each member of the dimension, and displays the same widgets on each page with the data filtered by the section dimension. Sections are available in both the Optimized and Classic Design Experiences.
Reference:
1: Choosing Between Optimized and Classic Design Modes – SAP Learning 2: Filtering Data in Optimized Design Mode – SAP Learning 3: Using Input Controls – SAP Learning 4: Chart Controls – SAP Learning : [Creating Sections – SAP Learning]

Using the SAP Analytics Cloud mobile app, the page type that is required for viewing stories is responsive. Responsive pages are designed to adapt to different screen sizes and orientations, making them suitable for mobile devices. Canvas and grid pages are not supported by the mobile app; they are designed for desktop browsers and fixed layouts. Verified Reference: [SAP Analytics Cloud – Mobile App]

The Digital Boardroom is a feature that allows you to create immersive and interactive presentations based on stories. You can use the Digital Boardroom to present your data and insights on multiple screens connected to a single device. The Digital Boardroom supports up to three screens that can display different views of the same story or different stories. Therefore, the correct answer is 3, as it is the maximum number of screens you can connect to the Digital Boardroom. Verified Reference:

Points of Interest Layer – Sets of geographical data that can be added to a geo map and analyzed with reference to business data from a model. For example, you can add points of interest layer that shows the locations of your customers or stores on a geo map.
Choropleth/Drill Layer – Applies blocks of shading to different geographical locations based on the value of the selected measure. For example, you can add choropleth/drill layer that shows the sales revenue by country or region on a geo map.
Feature Layer – Uses external data from valid service URLs. This data is layered on top of your existing geo map to provide additional context. For example, you can add feature layer that shows the traffic conditions or weather information on a geo map.
Flow Layer – Shows the connection between two locations based on the value of the selected measure. For example, you can add flow layer that shows the trade volume or migration patterns between countries or regions on a geo map.
Heat Map Layer – Uses color to visualize the data density of the selected measure. For example, you can add heat map layer that shows the population density or crime rate by area on a geo map. Verified Reference: [SAP Analytics Cloud – Geo Maps]

You can define a calculation for a table in three ways:
Table: You can add a simple calculation by selecting two measures in a table, right-clicking, choosing Add calculation, and choosing the calculation you want. You can also add a repeating or single column or row to a table by right-clicking on a measure or dimension and choosing Add Calculation1.
Calculation editor: You can open the calculation editor from the drop-down menu of Measures or Dimensions in the Designer Panel and create complex calculations for a chart or table. For each type of calculation, a new calculated member is created. You can also use dimension attributes as part of a calculation2.
Story: You can create a calculated measure in the Builder pane of a story. When setting up your calculation, you apply the typical formula functions, conditions, and operators to the data contained in your model. Calculated measures allow you to perform mathematical and Boolean operations on your data1.
Reference:
1: Calculating Data in Stories – SAP Learning 2: SAP Analytics Cloud In-story Calculation Series – An Introduction

When converting a story to Optimized Design Experience, you need to be aware that some elements that are available in the Classic Design Experience are not yet supported in the Optimized Design Experience. These elements include:
Grid pages
Linked analysis
Geo maps
Images
Shapes
Texts
Buttons
Input controls
Value driver trees
Explorer
If your story contains any of these elements, you will receive a warning message before converting the story, informing you that these elements will be permanently deleted from the story. You can choose to proceed with the conversion or cancel it. If you proceed, the unsupported elements will be removed from the story, and you will not be able to restore them1.
Reference:
1: Optimized Story Experience | SAP Help Portal

The SAP Analytics Cloud mobile app allows users to view and interact with stories, collaborate with colleagues using comments and notifications, and share links to stories via email or other apps. Users cannot create stories, datasets, or models using the mobile app. Verified Reference: [SAP Analytics Cloud – Mobile App]