Which two statements are true regarding a PL/SQL package body?

Which two statements are true regarding a PL/SQL package body? (Choose two.)

A.
It can be changed and recompiled without making the package specification invalid.

B.
It cannot invoke subprograms defined in other packages.

C.
It cannot be created without a package specification.

D.
It can contain only the subprograms defined in the package specification.