What is space complexity of the following dynamic programming implementation of the dice throw problem where f is the number of faces, n is the number of dice and s is the sum to be found?

#include<stdio.h>
int get_ways(int num_of_dice, int num_of_faces, int S)
{
     int arr[num_of_dice + 1][S + 1];
     int dice, face, sm;
     for(dice = 0; dice <= num_of_dice; dice++)
         for(sm = 0; sm <= S; sm++)
           arr[dice][sm] = 0;
     for(sm = 1; sm <= S; sm++)
         arr[1][sm] = 1;
     for(dice = 2; dice <= num_of_dice; dice++)
     { 
         for(sm = 1; sm <= S; sm++)
         {
             for(face = 1; face <= num_of_faces && face < sm; face++)
                 arr[dice][sm] += arr[dice - 1][sm - face];
         }
     }
     return arr[num_of_dice][S];
}
int main()
{
     int num_of_dice = 3, num_of_faces = 4, sum = 6;
     int ans = get_ways(num_of_dice, num_of_faces, sum);
     printf("%d",ans);
     return 0;
}

A. O(n*f)

B. O(f*s)

C. O(n*s)

D. O(n*f*s)

Answer: Option C