approach should you recommend?

You are designing a SharePoint 2010 application that creates a content type. You need to design the application
so that users are not able to change the content type from within the SharePoint 2010 user interface. Which
approach should you recommend?

A.
Create a content type that is read-only and deployed as a feature.

B.
Create a content type that is sealed and deployed as a feature.

C.
Use SharePoint Designer 2010 to create a content type and uncheck Allow Modifications.

D.
Use SharePoint Designer 2010 to create a content type that is read-only.