Which of the following cannot be declared as final?

• A. A class intending to be extended.
• B. A method that should be overridden.
• C. A final variable.
• D. None of the above.

Answer: (A)

A class that intends to be extended cannot be declared as final because the purpose of marking a class as final is to prevent it from being subclassed. When a class is declared final, it indicates that no other class can extend it, ensuring that its implementation is locked and cannot be modified or overridden. This is useful for security and design reasons when you want to prevent additional functionality from being added or change its behavior through inheritance.

In contrast, methods can be explicitly marked as final to prevent them from being overridden in subclasses. Similarly, final variables in Java are those whose values cannot be changed once assigned. Therefore, options involving methods as final and variables as final are perfectly valid declarations in the context of Java. The correct answer highlights the fundamental rule of final classes, which serve as the base for ensuring certain design principles in object-oriented programming.