Example Code Ch 09-4

Example Code Ch 09-4
Given the following partial class definition:
public class A1
{
public int x;
private int y;
protected int z;
...
}
public class A2 extends A1
{
protected int a;
private int b;
...
}
public class A3 extends A2
{
private int q;
...
}
-Refer to Example Code Ch 09-4: Which of the following is true with respect to A1, A2, and A3?

A) A1 is a subclass of A2 and A2 is a subclass of A3
B) A3 is a subclass of A2 and A2 is a subclass of A1
C) A1 and A2 are both subclasses of A3
D) A2 and A3 are both subclasses of A1
E) A1, A2 and A3 are all subclasses of the class A