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

• A. Only ii)
• B. All of the mentioned
• C. ii) and iv)
• D. ii), iii) and iv)