Which method of the SQlCommand class used to read the data from top to bottom with connected architecture environment?

Execute Reader() method reads the data in forward-only stream of rows from a SQL Server database.
Dispose() Releases all resources used by the Component.
ExecuteNonQuery() method performs data modification operations such as Insert, Update, Delete.
ExecuteScalar method to retrieve a first row, first column of result set which is a single value.