You have a SharePoint solution that contains a custom site column and a custom content type.

You need to add the custom site column as a lookup field for the custom content type.

What should you create?

A.
a Feature activation dependency

B.
a new Feature event receiver

C.
a new module

D.
a new SharePoint mapped folder

Explanation:
MNEMONIC RULE: “Feature event receiver”

Walkthrough: Add Feature Event Receivers
http://msdn.microsoft.com/en-us/library/ee231604.aspx