What happens when you try to compile and run this application? : Questions « Utility Classes « SCJP

1. SCJP
2. Utility Classes
3. Questions

import java.util.Set;
import java.util.TreeSet;

public class MainClass {
  public static void main(String[] a) {
    Set<Apple> set = new TreeSet<Apple>();
    set.add(new Apple());
    set.add(new Apple());
    set.add(new Apple());
    System.out.println(set);
  }
}

class Apple {
}

A.      Compiler error.
B.      No exception is thrown.