Trace the recursive call, mystery(3, 2, 6) and show the printed output. 1 public class Mystery 2 { 3 public static void main(String[] args) 4 { 5 6 } 7 System.out.println( mystery(3, 2, 6)); 8 public static int mystery(int a, int b, int c) 9 { 10 if (a==1) 11 return b; 12 else 13 15} 14 } return a + mystery(a-1, b, c); a. Which line defines the base case of mystery() method? b. Trace the recursion above, provide all necessary steps