设有如下程序:
import java.util.*;
public class Sun
public static void main (String args[ ])
int score;
String a;
Random r=new Random ();
score=r.nextInt (4)+5;
switch(score)
case 0:
a="E";
break;
case 1:
a="D";
break;
case 2:
a="C";
break;
case 3:
a="B";
break;
default:
a="A";
System.out.println (
A.;
程序运行的结果是( )。A) a="A"
B.a="E" a="A"
C.a="E"
D.a="C"