12. Consider the method public String mystery (Strings) { Stringsl - s.substring(0, 1); String s2 = s.substring (1, s.length() 1); String s3 = s.substring (s.length() 1); if (s.length() > int cols -; int) ID expression 3 >; for (int r = 0; I ; return b; For example, if a holds 1 2 3 4 5 6 b - rotate (a) will hold 36 25 14. Which of the following should replace and ? a. POWS (A) a.cols (B) a.cols (C) a.cols ( (D) a[0).length (E) a[0].length a. rows a. rows() a. length a. length new int (rOWS, cols) new int (rows, cols) new int (rows, cola) new int [rows][cols) new int [1] (rows, cols) 13. Which of the following is not a method of java.util.ArrayList? (A) add (String x); (B) remove (Object x) (C) insert (int 1, String x); (D) indexOf(object x); (E) set (int i, String x)