If R is a relation on the set A = {1, 2, 3, 4, 5, 6, 7, 8, 9} given by x R y ⟺ y = 3x, then R = (a) {(3, 1), (6, 2), (8, 2), (9, 3)} (c) {(3, 1), (2, 6), (3, 9)} (b) {(3, 1), (6, 2), (9, 3)} (d) none of these