What should you do?

You have a custom site definition.
You create a custom site Feature.
You need to ensure that the Feature is activated for all new sites that are created by using the custom site definition.
What should you do?
A. Modify the Onet.xml file.
B. Modify the web.config file.
C. Add a Feature receiver to the custom site Feature.
D. Add a Feature dependency to the custom site Feature.