Which two aspects are applicable to Page Includes? (2 answers)

Which two aspects are applicable to Page Includes? (2 answers)
A . Standard Visualforce controls such as apex: form should not be used within a page include
B . Page Includes must be assigned to an OOTB Page, i.e. Home, Product Detail, etc., and enabled
C . Page Includes can be configured as Body Includes Begin.
D . If a controller is used for an included page, then a merge variable must be present on the page.

Answer: A,D