According to the UML Notation Guide, Overlapping Means

Multiple Choice

According to the UML Notation Guide, overlapping means:

A) a descendant may be descended from more than one of the subclasses.
B) a descendant may not be descended from more than one of the subclasses.
C) all subclasses have been specified, and no others are expected.
D) the list of objects is stable, but relationships will change.