You create an atomic transaction to read data from an external database. The processing time for the transaction may take several minutes. You need to ensure that the data in the source database has not changed at the time the transaction is committed. What should you do?

A.
Set the transaction time-out to Zero.

B.
Set the Isolation Level property to Repeatable Read.

C.
Set the Isolation Level property to Read Committed.

D.
Set the Transaction Type property to Long running.