Suppose R = {1, 3, 5, 7, 9, 11, 13, 15, 17} and D = {3, 6, 9, 12, 15, 18, 21, 24, 27}. What is ? (1 point) Responses {3, 9, 15} {3, 9, 15} {1, 5, 7, 11, 13, 17} {1, 5, 7, 11, 13, 17} {1, 3, 5, 6, 7, 9, 11, 12, 13, 15, 17, 18, 21, 24, 27} {1, 3, 5, 6, 7, 9, 11, 12, 13, 15, 17, 18, 21, 24, 27} {6, 12, 18, 21, 24, 27}