How many times is the function wordScramble() called in the given program? public class WordScramble { public static void wordScramble(String rem, String scr) { if (rem.isEmpty()) { System.out.println(scr + rem); } else { for (int i = 0; i < rem.length(); ++i) { wordScramble((rem.substring(0, i) + rem.substring(i + 1, rem.length())), (scr + rem.charAt(i))); } } } public static void main(String args[]) { wordScramble("ab", ""); } } 4 2 5 3