Which access modifier allows visibility to a derived class in a different package?

• A. Private
• B. Protected
• C. Package-private
• D. Public

Answer: (B)

The access modifier that allows visibility to a derived class in a different package is "protected." When a member (variable or method) of a class is declared as protected, it can be accessed not only by the class itself and classes in the same package but also by subclasses (derived classes) regardless of the package they are in.

This characteristic of the protected access modifier is essential in object-oriented programming, as it facilitates inheritance and allows subclasses to inherit essential behaviors or properties from a parent class while keeping them hidden from outside classes that do not inherit from them. Thus, a derived class in a different package can still access protected members of its superclass, promoting encapsulation while enabling flexibility in design.

The other access modifiers serve different purposes. For instance, private members are not accessible outside their own class, package-private (default) members can only be accessed within classes in the same package, and public members are universally accessible but do not impose any restriction based on inheritance.