Question on Inheritance & Polymorphism

A) Given this code:

Animal myDog = new Dog(Spot);

myDog.speak();

What do we know about the Dog class and the Animal class?

B) Given a class Animal has a child Cat and a child BigCat. Cat has a child class Tabby and Big Cat has a child class Tiger.

Given:

Animal animal;

Cat kitty = new Cat();

BigCat big = new BigCat();

Tiger tig = new Tiger();

Tabby tab = new Tabby();

Identify each line of code that will cause an error:

	Error yes/no	Why?
animal = big;
kitty = null;
tab = tig;
big = tig;
big = tab;
tig = kitty;