Can an abstract class be declared as final?

• A. Yes, it can.
• B. No, it cannot be declared as final
• C. Only if it has a constructor
• D. Only in specific scenarios

Answer: (B)

An abstract class cannot be declared as final because the primary purpose of an abstract class is to serve as a base for other classes to inherit from and extend functionality. The final keyword, when applied to a class, prevents it from being subclassed. This creates a contradiction since an abstract class, by definition, is intended to be subclassed to provide concrete implementations for its abstract methods.

When a class is marked as final, it signals to the compiler that no further subclasses can be derived from it, thus negating the fundamental utility of an abstract class, which is to facilitate inheritance and promote polymorphism in object-oriented programming.

Other options introduce additional considerations, but they do not align with the core principles of Java's class design. For instance, a final class could not be abstract because it would not fulfill the requirement of being subclassed, which is crucial to the concept of abstract classes. Thus, the conclusion is that an abstract class cannot logically be declared final.