The DataMember property in data binding is used to specify the name of the data source column to which a UI control is bound. It indicates which column from the data source should be displayed or manipulated in the UI control, facilitating proper data representation and interaction in WinForms applications.

The ExecuteNonQuery method in ADO.NET returns the number of rows affected by the command, typically used with INSERT, UPDATE, DELETE queries. It does not return a result set or a scalar value. If there's an error, it may throw an exception.

A DataAdapter in ADO.NET acts as a bridge between a database and a DataSet. To update data, the DataAdapter first fills the DataSet with data from the database, modifies the data within the DataSet, and then updates the database with the changes made in the DataSet.

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.

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.

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.

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.

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.

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.

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.