Given:

1. public class TestString1 {

2. public static void main(String[] args) {

3. String str = "420";

4. str += 42;

5. System.out.print(str);

6. }

7. }

What is the output?

A. 42 B. 420 C. 462 D. 42042 E. Compilation fails. F. An exception is thrown at runtime.