Consider the following code:

public class B1
{
private int i;
private int j;
...
}
public class B2 extends B1
{
private int m;
private int n;
...
}
public class B3 extends B2
{
private int z;
...
}

Which of the following sets of instance variables are directly accessible in class B2? (2 points)

1) i, j, m, n, z
2) i, j, m, n
3) i, m, n
4) m, n
5) z