You are developing a database application by using Microsoft SQL Server 2012.
An application that uses a database begins to run slowly.
Your investigation shows the root cause is a query against a read-only table that has a clustered index.

The query returns the following six columns:
One column in its WHERE clause contained in a non-clustered index
Four additional columns
One COUNT (*) column based on a grouping of the four additional columns
You need to optimize the statement.
What should you do?

A.
Add a HASH hint to the query.

B.
Add a LOOP hint to the query.

C.
Add a FORCESEEK hint to the query.

D.
Add an INCLUDE clause to the index.

E.
Add a FORCESCAN hint to the Attach query.

F.
Add a columnstore index to cover the query.

G.
Enable the optimize for ad hoc workloads option.

H.
Cover the unique clustered index with a columnstore index.

I.
Include a SET FORCEPLAN ON statement before you run the query.

J.
Include a SET STATISTICS PROFILE ON statement before you run the query.
K.
Include a SET STATISTICS SHOWPLAN_XML ON statement before you run the query.
L.
Include a SET TRANSACTION ISOLATION LEVEL REPEATABLE READ statement before you run the query.
M.
Include a SET TRANSACTION ISOLATION LEVEL SNAPSHOT statement before you run the query.
N.
Include a SET TRANSACTION ISOLATION LEVEL SERIALIZABLE statement before you run the query.