Consider the following code:

#include<stdio.h>
int recursive_sum(int n)
{
      if(n == 0)
        return 0;
      return ________;
}
int main()
{
    int n = 5;
    int ans = recursive_sum(n);
    printf("%d",ans);
    return 0;
}

Which of the following lines is the recurrence relation for the above code?

A. (n - 1) +recursive_sum(n)

B. n + recursive_sum(n)

C. n + recursive_sum(n - 1)

D. (n - 1) + recursive_sum(n - 1)

Answer: Option C