Which two statements are true?

Which two statements are true?

A.
An abstract class can implement an interface.

B.
An abstract class can be extended by an interface.

C.
An interface CANNOT be extended by another interface.

D.
An interface can be extended by an abstract class.

E.
An abstract class can be extended by a concrete class.

F.
An abstract class CANNOT be extended by an abstract class.

Explanation:
E: When an abstract class is subclassed, the subclass usually provides implementations for all of the abstract methods in its parent class.
Incorrect answers:
F: When an abstract class is subclassed, the subclass usually provides implementations for all of the abstract methods in its parent class. However, if it does not, the subclass must also be declared abstract.