Which of the following is/are true for an abstract class?
1. A class is declared abstract by prefacing the definition with the word abstract.
2. A class is declare abstract by using the keyword implements.
3. It is a class that really isn’t supposed to ever be instantiated but instead serves as a base class.
4. Attempting to instantiate an abstract class results in an error.

A. Only 2

B. All of the mentioned

C. 2 and 4

D. 2, 3 and 4

Answer: Option A