In Java, why do we use the protected access modifier and where is a protected member visible?

Introduction / Context:
Java provides several access modifiers to control the visibility of class members: public, protected, package access and private. The protected modifier sits between public and package access in terms of visibility and is especially important in inheritance hierarchies. It allows subclasses to see certain members while still hiding them from unrelated code in other packages. This question asks you to explain why protected is used and to describe its visibility rules.

Given Data / Assumptions:
- We are working with classes that may belong to the same package or to different packages.
- Some classes extend others, forming inheritance relationships.
- We want some members to be visible to subclasses, but not entirely public to all external code.
- We need to recall the specific visibility rules associated with the protected modifier.

Concept / Approach:
A protected member in Java is visible in all classes within the same package, similar to package access, and in addition is visible in subclasses even if those subclasses are in different packages. This is different from package access, which does not extend visibility across package boundaries, and from public, which is visible everywhere. Protected is therefore useful when designing frameworks and base classes that should expose some internal details to derived classes while not making them completely public to all consumers.

Step-by-Step Solution:
Step 1: Recall that without any modifier, a package access member is visible only within the same package and not in subclasses in different packages. Step 2: Understand that the protected modifier extends this visibility by allowing subclasses in other packages to see and use the member. Step 3: Recognize that protected does not make the member globally public; unrelated classes in other packages still cannot access it. Step 4: Notice that protected is often used for template methods or extension points intended for subclasses, not for general application code. Step 5: Choose the option that correctly states visibility within the same package and in subclasses across packages.

Verification / Alternative check:
As an example, suppose class Base in package framework defines a protected method calculate(). A class Helper in the same package framework can call calculate() because it is in the same package. A subclass CustomBase in another package app can also call calculate() because it extends Base. However, an unrelated class in package app that does not extend Base cannot call calculate(). This pattern is exactly what protected is designed to support and matches the description in option A.

Why Other Options Are Wrong:
Option B describes private visibility, not protected, since private members are visible only inside the declaring class.
Option C treats protected like public, but public members are visible from any class anywhere, which is broader than protected.
Option D states that protected members are visible only in subclasses in the same package and hidden from other classes in that package, which is not correct because protected members remain visible to all classes in the same package, not just subclasses.

Common Pitfalls:
Developers sometimes misunderstand protected and assume it restricts access more sharply than it actually does, forgetting that it includes package level visibility. Another pitfall is overusing protected when composition and delegation might provide a cleaner design. Protected is most appropriate for carefully designed inheritance hierarchies where subclasses legitimately need deeper access to base class behavior. Understanding its visibility ensures that APIs are neither too exposed nor too restrictive.

Final Answer:
The correct statement is protected members are visible within the same package and also in subclasses even if those subclasses are in different packages.