What will happen when you try to compile and run this code? : Questions « Type Casting « SCJP

1. SCJP
2. Type Casting
3. Questions

class ApBase implements Runnable {
  public void run() {
  }

}

public class MainClass {
  public static void main(String[] argv) {
    ApBase aBase = new ApBase();
    Runnable aR = aBase;
    Object obj = aR;
    ApBase x = (ApBase) obj;

  }
}
    
A.      The compiler objects to line 2.
B.      The compiler objects to line 3.
C.      The code compiles but when run throws a ClassCastException in line 4.
D.      The code compiles and runs without a problem.