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. An advantage of inheritance over interfaces is that only inheritance provides the is-a relationship.