单选题：What is the output of this program？

What is the output of this program？
@[B](2)

```
void fun(int);
main( )
{
int w=2;
fun(w);
}
void fun(int k)
{ if (k>0) fun(k-1);
printf(“%d”,k);
}
```

A. 210
B. 012
C. 0
D. 201




A.210
B.012
C.0
D.201


答案：B