QUESTION $6$

Subclasses$/$inheritance can have negative consequences because $($select all correct answer$($s$)$ and no incorrect answer$($s$)$ to get credit$)$:

A$.$ A subclass depends on the implementation details of its superclass.

B$.$ Introduces potential issues with the equality contract.

C$.$ Difficult for superclass to maintain invariants in face of malicious$/$careless subclass.

D$.$ Inheritance is forever, cannot change the interface in subsequent releases.