Consider the classes below, declared in the same file:

class A

$\{$

int a;

public A$()$

$\{$

a $=7$;

$\}$

$\}$

class B extends A

$\{$

int b;

public B$()$

$\{$

b $=8$;

$\}$

$\}$

Which of the statements below is false?

Group of answer choices

Both variables a and b are instance variables.

After the constructor for class B executes, the variable a will have the value $7.$

After the constructor for class B executes, the variable b will have the value $8.$

A reference of type A can be treated as a reference of type B$.$