In object oriented programming, what does inheritance allow you to do when designing related classes?

Introduction / Context:
Inheritance is one of the core pillars of object oriented programming, together with encapsulation and polymorphism. It allows new classes to be defined based on existing ones, making it easier to reuse code and express relationships between concepts. This question checks whether you understand the main purpose of inheritance in class design rather than confusing it with unrelated features such as operating system access or database generation.

Given Data / Assumptions:

• We are using a class based object oriented language such as C++ or Java.
• Classes can extend or derive from other classes.
• The term inheritance refers to this language feature, not to database or file system concepts.

Concept / Approach:
Inheritance allows a class, often called a derived or child class, to reuse and extend the behaviour of another class, often called a base or parent class. Common state and operations are defined once in the base class, and derived classes inherit these members automatically. They can then add new members or override virtual methods to provide specialised behaviour. This forms a hierarchy where base classes capture general concepts and derived classes capture more specific concepts. For example, Animal can be a base class, while Dog and Cat are derived classes that inherit and refine the behaviour of Animal.

Step-by-Step Solution:
Step 1: Focus on what inheritance does at the language level: it connects classes in a parent child relationship.Step 2: Recognise that the key benefits are code reuse and the ability to express is a relationships, such as Dog is an Animal.Step 3: Option C states that inheritance allows you to create a hierarchy of related classes that share behaviour and reuse base class code.Step 4: Option A describes standalone classes with no relationship, which is the opposite of inheritance.Step 5: Other options talk about unrelated features, so option C is the correct choice.

Verification / Alternative check:
In C++, if you write class Animal { public: void eat(); }; and then class Dog : public Animal { };, every Dog object has the eat method inherited from Animal. You do not have to rewrite the implementation. You can add new methods like bark in Dog while still treating Dog objects as Animals in code that uses polymorphism. This demonstrates how inheritance creates a hierarchy and promotes reuse.

Why Other Options Are Wrong:
Option A ignores the relationship aspect and describes isolated classes. Option B mentions operating system methods, which are accessed through libraries, not through inheritance alone. Option D describes the opposite of polymorphism, which inheritance usually enables through virtual methods. Option E talks about automatic database generation, which may be supported by frameworks but is not the built in purpose of inheritance in the programming language.

Common Pitfalls:
Developers sometimes misuse inheritance to share code between classes that do not have a clear is a relationship, leading to rigid hierarchies. In such cases, composition can be a better choice. For exam purposes, remember that the textbook answer is that inheritance lets you build class hierarchies and reuse base class code in derived classes.

Final Answer:
Create a hierarchy of related classes that share common behaviour and can reuse code from base classes.