A ____________ would be used to check to see if x = 0 and n = 0 at the same time, and can also check to see if n is negative, before calling the recursive function.

```
1 float p( float x, int n )
2 {
3 if ( n == 0 )
4 return 1;
5 else
6 return x p( x, n – 1 );
7 }
```
A. driver
B. class template
C. class function
D. overloaded operator function

6