How would you ensure that the query to use the original data when updates occur?

You work as a database developer at ABC.com. ABC has an in-house application named
ABCApp3 that runs a Transact-SQL query against a SQL Server 2012 database named SalesDB.
ABC.com users report that ABCApp3 is functioning sluggishly. You discover that concurrent
updates are causing blockages on the SalesDB database.
How would you ensure that the query to use the original data when updates occur?

A.
You should have the query run in the REPEATABLE READ ISOLATION LEVEL.

B.
You should have the query run in the SERIALIZABLE ISOLATION LEVEL.

C.
You should have the query run in the READCOMMITTED ISOLATION LEVEL.

D.
You should have the query run in the SNAPSHOT ISOLATION LEVEL.

E.
You should have the query run in the READPAST ISOLATION LEVEL.

Explanation: