Which of the following is a characteristic of a concrete class?

A) It cannot be instantiated.

B) It may contain abstract methods.

C) It must implement all abstract methods from its parent class.

D) It cannot have methods.

Answer: C) It must implement all abstract methods from its parent class.

Explanation: A concrete class is a class that can be instantiated and must provide implementations for all abstract methods inherited from its parent abstract class. This ensures that the concrete class is complete and can be used to create objects.