Question: We mention that a vehicle management program should store information on the car dealers in a variable of type Dealer, rather than Ford Dealer, even if all cars are Fords. How should Dealer and Ford Dealer be related? For example, should Dealer be an interface and Ford Dealer a class that implements the interface? Should Dealer be an abstract class and Ford Dealer a subclass? Is there a third alternative that might be better? Briefly explain.