Which of the following statements is false?

a. An advantage of inheritance over interfaces is that only inheritance provides the is-a relationship.
b. Objects of any subclass of a class that implements an interface can also be thought of as objects of that interface type.
c. When a method parameter is declared with a subclass or interface type, the method processes the object passed as an argument polymorphically.
d. All objects have the methods of class Object.

A