What is output?

public abstract class People $\{$

protected String name;

protected int age;

public abstract void PrintInfo$()$;

public void PrintInformation$()\{$

System.out.println$("$In Base Class People"$)$;

$\}$

$\}$

public class Teacher extends People $\{$

private int experience;

public void PrintInfo$()\{$

System.out.println$("$In Child Class Teacher"$)$;

$\}$

$\}$

public class Principal extends Teacher $\{$

public void PrintInformation$()\{$

System.out.println$("$In Child Class Principal"$)$;

$\}$

public static void main$($String args$[])\{$

Principal tim;

tim $=$ new Principal$()$;

tim.PrintInfo$()$;

$\}$

$\}$

a$.$

In Child Class Principal

b$.$

In Child Class Teacher

c$.$

In Base Class People

d$.$

Error: Compiler error