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

The Sales.Customers table will contain 100,000 rows. You expect the FaxNumber column to
contain a null value for 70 percent of the rows.
You need to create an index to support Sales.CustomersByFaxNumber. The solution must
minimize the disk storage requirements.
Which code segment should you execute?

A.
CREATE INDEX IX_Customers ON Customers (FaxNumber)
WHERE FaxNumber IS NOT NULL

B.
CREATE INDEX IX_Customers ON Customers (FaxNumber)
WITH FILLFACTOR=0

C.
CREATE INDEX IX_Customers ON Customers (CustomerName)
INCLUDE (FaxNumber)

D.
CREATE INDEX IX_Customers ON Customers (FaxNumber)

E.
CREATE INDEX IX_Customers ON Customers (FaxNumber)
WHERE FaxNumber IS NULL