The SelectCommand property of a DataAdapter is used to specify the SQL command that retrieves data from the database. This command is executed when the DataAdapter's Fill method is called to populate the DataSet with data.

DataGrid and DataGridView controls are primarily used for displaying tabular data in a grid format. They allow users to view and interact with data from various data sources such as databases or collections.

The correct option is NewRow(). This method is used to create a new DataRow object with the same schema as the DataTable but without adding it to the table. It is commonly used to prepare a new row for insertion into the DataTable. The AddNew() method is used in BindingSource to add a new row, InsertRow() and CreateRow() are not valid methods in ADO.NET.

The correct option is DataGridView with DataSource property. DataGridView is a versatile control for displaying tabular data and supports data binding through its DataSource property, which allows you to easily bind it to a data source such as a DataTable or a list of objects. This control provides rich functionality for displaying and editing data in a grid format, making it suitable for displaying a list of products from a database.

The "RowEnter" event is triggered when a user selects a row in a DataGrid or DataGridView control. This event occurs when the focus moves to a new row, indicating that the user has selected that row. It provides an opportunity to perform actions based on the selected row, such as retrieving data or updating other controls.

When you close the associated database connection, the data reader throws an exception. This is because the data reader relies on the connection to fetch data from the database. Closing the connection while the data reader is still in use results in an exception being thrown to indicate the invalid operation. It's essential to close the data reader before closing the connection to avoid this issue.

Connection pooling in ADO.NET improves performance by reusing connections, reducing overhead by eliminating the need to create a new connection for every request, enhancing scalability by efficiently managing connections, and increasing reliability by avoiding connection leaks.

In Entity Framework, the Entity Data Model (EDM) represents the structure of the underlying database. EDM provides a conceptual view of the data, including entities, relationships, and mappings to the database schema. It abstracts away the complexity of the database schema and allows developers to work with entities rather than directly dealing with database tables.

The DbContext class provides a context to interact with the database. It represents a session with the database and provides facilities to query, insert, update, and delete data from the database. DbContext acts as an entry point to the Entity Framework Core and manages the connection, transaction, and other aspects of interacting with the database.

SqlTransaction object is responsible for managing transactions in ADO.NET. It provides methods to begin, commit, or rollback transactions, ensuring that database operations are performed atomically and consistently.