You just have to answer R-2.13, but if you want to show your work for R-2.12 as well, go ahead and do it. Thanks!

R-2.12 Draw a class inheritance diagram for the following set of classes: Class Goat extends Object and adds an instance variable tail and methods milk( ) and jump( ). Class Pig extends Object and adds an instance variable nose and methods eat(food) and wallow( ). Class Horse extends Object and adds instance variables height and color, and methods run( ) and jump( ). Class Racer extends Horse and adds a method race( ). Class Equestrian extends Horse and adds instance variable weight and is- Trained, and methods trot( ) and isTrained( ).

R-2.13 Consider the inheritance of classes from Exercise R-2.12, and let d be an object variable of type Horse. If d refers to an actual object of type Equestrian, can it be cast to the class Racer? Why or why not?