12. Let S = {0, 1, 2, 4, 6). Test the following binary relations on S for reflexivity, symmetry, antisymmetry, and transitivity a. = {(0, 0), (1, 1 ), (2, 2), (4, 4), (6, 6), (0, l ), (1,2), (2, 4), (4, 6)} c. = {(0, l ), (1,2), (0, 2), (2, 0), (2, 1), (1,0), (0, 0), (l, 1), (2, 2)}