Given the following method:

public static int mystery(int n) 
{
    if (n <= 0) 
    {
        return n;
    }
    return  n % 10 + mystery(n / 10);
}

Including the initial call, how many times will the function be called for mystery(1234)?

1. Correct Answer
   Incorrect Answer
   a

   2

2. Correct Answer
   Incorrect Answer
   b

   3

3. Correct Answer
   Incorrect Answer
   c

   4

4. Correct Answer
   Incorrect Answer
   d

   5

5. Correct Answer
   Incorrect Answer
   e

   10