Question $8$

What will be the return value of function call foo $(n,n)$ for the following recursive function foo$()?$ Assume that the variable $n$ is initialized to $4$ before function call.

int foo $($int &p$,$ int q$)\{$

$q=q-1$

if $)==(0$

return $1$;

$p=p+1$

return $f(p,q)*p$;

Select the correct option: