Consider the following code:

#include<stdio.h>
int arr[31], len = 0;
void recursive_dec_to_bin(int n)
{
      if(n == 0 && len == 0)
      {
          arr[len++] = 0;
          return;
      }
      if(n == 0)
         return;
      arr[len++] = n % 2;
      recursive_dec_to_bin(n/2);
}

Which of the following lines is the base case for the above code?

A. if(n ==0 && len == 0)

B. if(n == 0)

C. if(n ==0 && len == 0) and if(n == 0)

D. if(n == 1)

Answer: Option C