单选题：Given code below:

Given code below:
```Java
class A {
public void baz() { System.out.println("A"); }
}
class B extends A {
public void baz() { System.out.println("B"); }
public static void main(String[] args) {
A a = new B();
a.baz();
}
}

```
What will happen when you compile and run this program? @[B](2)

A. The program compiles, runs, and output A.
B. The program compiles, runs, and output B.
C. The program compiles, but throws a runtime exception.
D. The program does not compile.





A.The program compiles, runs, and output A.
B.The program compiles, runs, and output B.
C.The program compiles, but throws a runtime exception.
D.The program does not compile.


答案：B