What is the result?

Given:

1. class TestA {
2. public void start() { System.out.println(“TestA”); }
3. }
4. public class TestB extends TestA {
5. public void start() { System.out.println(“TestB”); }
6. public static void main(String[] args) {
7. ((TestA)new TestB()).start();
8. }
9. }

What is the result?

A.
TestA

B.
TestB

C.
Compilation fails.

D.
An exception is thrown at runtime.