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

int min_of_two(int a, int b)
{
      if(a < b)
        return a;
      return b;
}
int recursive_min_element(int *arr, int len, int idx)
{
      if(idx == len - 1)
      return arr[idx];
      return min_of_two(arr[idx], recursive_min_element(arr, len, idx + 1));
}
int main()
{
     int n = 10, idx = 0, arr[] = {5,2,6,7,8,9,3,-1,1,10};
     int min_element = recursive_min_element(arr,n,idx);
     printf("%d",min_element);
     return 0;
}

A. 9

B. 10

C. 11

D. 12

Answer: Option B