Given the following relations on S = (a, b): {(a, a) {(a, b)} . (b, a) {(b, b)} {(a, a),(a, b) {(a, a), (b, a); {(a, a), (b, b)} {(a, b), (b, a) {(a, b), (b, b) {(b, a), (b, b)} {(a, a),(a, b), (b, a) {(a, a),(a, b), (b, b)} {(a, a), (b, a), (b, b)} {(a, b), (b, a), (b, b)} {(a, a),(a, b), (b, a), (b, b)} Which ones are: a. reflexive? b. symmetric? c. antisymmetric? d. transitive