Concept:
Object-oriented programming is based on concepts such as classes, objects, inheritance, polymorphism, encapsulation, and abstraction.
Step 1: Check Assertion (A).
C++ supports object-oriented programming. It allows the creation of classes and objects.
\[
A \text{ is correct}
\]
Step 2: Check Reason (R).
Inheritance is one of the important features of object-oriented programming. C++ supports inheritance, where one class can acquire properties of another class.
\[
R \text{ is correct}
\]
Step 3: Check explanation.
Since inheritance is an important feature of object-oriented programming, support for inheritance helps explain why C++ is called an object-oriented language.
\[
\therefore \text{Correct Answer is (A)}
\]