Which OOP concept allows a class to be defined based on previously defined classes, inheriting characteristics and expanding on them?

• A. Information Hiding
• B. Inheritance
• C. Encapsulation
• D. Abstraction

Answer: (B)

Inheritance lets you define a new class based on an existing one. The new class automatically gets the existing class’s fields and methods and can add new features or override existing behavior to specialize how it works. For example, a base class might describe a generic Employee with a name and pay, while a derived class like Manager can reuse those basics and also include department-specific data or override a method to reflect a different bonus calculation. This mechanism is exactly what “defined based on previously defined classes, inheriting characteristics and expanding on them” describes.

Information hiding focuses on restricting access to an object's internal state. Encapsulation combines data and the methods that operate on that data, often using access controls, but it isn’t about starting from another class. Abstraction is about modeling essential features while ignoring details, not about deriving a new class from an existing one.