class Parent {

public int x;

}

class Child extends Parent {

public void doStuff() {

System.out.println("I'm a child");

}

}

class Main {

public static void main(String[] args) {

Parent p1 = new Parent();

Child c1 = new Child();

Parent p2 = new Child();

p1.doStuff(); //Line 1

c1.doStuff(); //Line 2

p2.doStuff(); //Line 3

((Child)p2).doStuff(); //Line 4

}

}

Which line or lines of code below will cause compile errors? Line 1 Line 3 Line 1 Line 3 Line 4 Line 1 Line 2 Line 3 Line 4 Line 1