Which term is used to describe this object-oriented concept?

Two classes named Circle and Square inherit from the Shape class. Circle and Square both
inherit Area from the Shape class, but each computes Area differently.
Which term is used to describe this object-oriented concept?

A.
polymorphism

B.
encapsulation

C.
superclassing

D.
overloading

Explanation:
You can use polymorphism to in two basic steps:
Create a class hierarchy in which each specific shape class derives from a common base
class.
Use a virtual method to invoke the appropriate method on any derived class through a single
call to the base class method.