A.int->IntegerB.float->FloatC.char->CharacterD.boolean->boolean
A.Out.classB.Inner.classC.Out.Inner.classD.Out$Inner.class
A.Cat cat =(Cat)new Animal();B.Animal a =new Cat();Cat cat =(Cat)a;C.Animal animal =new Cat();D.Animal a =new Dog();Cat cat =(Cat)a;