1) Let A = {1, 3, 5, 15, 18} and R be defined by xRy if and only if x|y. a) Draw the digraph of A. b) Draw the Hasse diagram of A. c) Give a subset of B that is linearly ordered and contains at least three elements. {(1, 3, 18), (1, 5, 15), (3, 15, 18), (1, 3, 15)} Are a,b, c answers correct or incorrect? Please let me know and thank you