How many times is the function recursive_sum_of_digits() called when the following code is executed?

#include<stdio.h>
int recursive_sum_of_digits(int n)
{
      if(n == 0)
        return 0;
      return n % 10 + recursive_sum_of_digits(n/10);
}
int main()
{
      int n = 1201;
      int ans = recursive_sum_of_digits(n);
      printf("%d",ans);
      return 0;
}

A. 6

B. 7

C. 5

D. 9

Answer: Option C