The correct option is CommandTimeout. In ADO.NET, the CommandTimeout property of a command object allows you to specify the maximum amount of time (in seconds) that a command can execute before it is terminated. This property is useful in scenarios where you want to control the execution time of commands, preventing long-running queries from affecting application performance or causing timeouts.

Table Splitting in Entity Framework allows an entity to be mapped to multiple tables with a one-to-one relationship, where each table represents a subset of the entity's properties. This is useful when dealing with large entities or when certain properties should be stored separately for optimization purposes. Entity Splitting, on the other hand, involves mapping a single entity to multiple tables based on its properties, but with each table containing different sets of properties belonging to the same entity. This allows for more granular control over the database schema and can be beneficial in scenarios where certain properties are rarely accessed or updated separately from the main entity.

Parameters in non-query commands of ADO.NET are used to provide values dynamically to the command, helping in executing parameterized queries to interact with the database securely and efficiently.

The primary difference between a dataset and a data reader in ADO.NET is that a dataset provides disconnected access to data, meaning it retrieves and stores data in memory independently of the data source. On the other hand, a data reader provides connected access to data, requiring an active connection to the data source while reading data sequentially. This fundamental distinction impacts factors such as performance, memory usage, and flexibility in data manipulation.

The correct option is Entity Data Model. EDM (Entity Data Model) is an abstract conceptual representation of the data in a database. It provides a consistent and uniform way to access and manipulate data across various data sources.

The Where operator is used to filter elements in a sequence based on a specified condition. It takes a predicate as an argument and returns a new sequence containing only the elements that satisfy the specified condition. This is commonly used for filtering data in LINQ queries.

The DataSource property of a data-bound control specifies the source of data for binding, allowing the control to display data retrieved from the specified data source.

In parameterized queries, placeholders are typically denoted by question marks (?). These question marks serve as positional markers for where the input data should be inserted into the SQL statement. When executing the query, the actual values are bound to these placeholders, ensuring proper sanitation and preventing SQL injection attacks.

Eager loading should be considered when dealing with complex object graphs, meaning scenarios where an entity has multiple related entities and navigating through them would lead to multiple database round-trips if lazy loading were used. Eager loading retrieves all related entities in a single query, which can reduce the number of database round-trips and improve performance in such scenarios. This approach is suitable when memory usage is not a significant concern, as it may lead to loading unnecessary data into memory.

The correct option is 1. SelectedIndexChanged. This event is commonly used for postback and data binding in ASP.NET when dealing with the DropDownList control. It triggers when the selected item in the DropDownList control changes.

The correct option is Represents a single row of data. DataRow object in ADO.NET represents a single row of data within a DataTable. It allows modification, addition, and deletion of data in the DataTable. The other options do not accurately describe the role of a DataRow object.

To enable users to edit data within the displayed table, you would set the EditingEnabled property to true in the chosen control, such as DataGridView. This property allows users to modify cell values directly within the grid, providing a seamless editing experience. By enabling editing functionality, users can make changes to the data without the need for additional forms or dialogs, enhancing the usability of the application.