Which stored procedure option should you use?

You are a database developer at an independent software vendor. You create stored procedures that contain
proprietary code. You need to protect the code frombeing viewed by your customers. Which stored procedure
option should you use?

A.
ENCRYPTBYKEY

B.
ENCRYPTION

C.
ENCRYPTBYPASSPHRASE

D.
ENCRYPTBYCERT

Explanation:
Verified answer as correct.
Reference: http://technet.microsoft.com/en-us/library/bb510663.aspx
Reference: http://technet.microsoft.com/en-us/library/ms174361.aspx
Reference: http://msdn.microsoft.com/en-us/library/ms187926.aspx
Reference: http://technet.microsoft.com/en-us/library/ms190357.aspx
Reference: http://technet.microsoft.com/en-us/library/ms188061.aspx