Which statement about mapping using the Java Persistence API is correct?

Which statement about mapping using the Java Persistence API is correct?

A.
User-defined XML mapping files can be used only if orm. xml file is NOT present.

B.
All mapping files other than orm. xml must be listed explicitly in the persistence, xml descriptor.

C.
Mapping information specified in the XML mapping file overrides all annotations and default
mappings.

D.
The orm.xml file must be placed into the persistence unit’s root to be processed by the
persistence provider.