You administer a Microsoft SQL Server 2012 database named Orders.

Orders contain a table named OrderShip that is defined as follows:

A NULL value represents a domestic order. Ninety percent of the values in CountryCode are NULL.

Customers require a procedure that will return orders for all customers from a specified country. You create a new procedure:

Performance on this procedure is slow.

You need to alter the schema to optimize this query. Objects created must use a minimum amount of

resources.

Which Transact-SQL statement should you use?

A. CREATE NONCLUSTERED INDEX IX_CountryCode ON Ordership (CountryCode)

WHERE CountryCode IS NOT NULL

B. CREATE STATISTICS ST_CountryCode ON OrderShip (CountryCode)

WHERE CountryCode IS NOT NULL

C. CREATE CLUSTERED INDEX IX_CountryCode ON OrderShip (CountryCode)

D. CREATE INDEX IX_CountryCode ON OrderShip (CustomerID)

WHERE CountryCode IS NOT NULL