Consider the following recursive method, which is intended to return a String with any consecutive duplicate characters removed. For example, removeDupChars("aabcccd") returns "abcd".public static String removeDupChars(String str){if (str == null || str. length() <= 1){return str;}else if (str. substring(0, 1).equals(str. substring(1, 2))){return removeDupChars(str. substring(1));}else{/* missing code */}}Which of the following can replace /* missing code */ so that removeDupChars works as intended?A. return removeDupChars(str. substring(2));B. return removeDupChars(str. substring(1)) + str. substring(0, 1);C. return removeDupChars(str. substring(2)) + str. substring(1, 2);D. return str. substring(0, 1) + removeDupChars(str. substring(1));E. return str. substring(1, 2) + removeDupChars(str. substring(2));