Which statement is true about the primary key of a Java Persistence entity?

Which statement is true about the primary key of a Java Persistence entity?

A.
The primary key cannot be overriden by a mapping descriptor.

B.
The location of the primary key defines the topmost entity class in the hierarchy.

C.
If property-based access is used, the properties of the primary key class must be public or
protected.

D.
At least part of a primary key must be defined in the class that is the topmost class of an entity
which is defined by a hierarchy of classes.