You have a SQL Azure database.
You execute the following script:

You add 1 million rows to Table1. Approximately 85 percent of all the rows have a null value for Column2.
You plan to deploy an application that will search Column2.
You need to create an index on Table1 to support the planned deployment. The solution must minimize the
storage requirements.
Which code segment should you execute?

A.
CREATE INDEX IX_Table1 ON Table1 (Column2)
WITH FILLFACTOR-0

B.
CREATE INDEX IX_Table1 OK Table1 (Column1)
INCLUDE (Column2)

C.
CREATE INDEX IX_Table1 ON Table1 (Column2)
WHERE Column2 IS NULL

D.
CREATE INDEX IX_Table1 ON Table1 (Column2)
WHERE Column2 IS NOT NULL

Explanation:
http://msdn.microsoft.com/en-us/library/ms188783.aspx
http://msdn.microsoft.com/en-us/library/cc280372.aspx