1. Suppose relation R(A,B,C) has the tuples: 123 456 126 and relation S(A,B,C) has the tuples: 1 2 3 Compute (R - S) [union) (S-R), often called the "symmetric difference" of R and S. Then, identify from the list below, one of the tuples in the symmetric difference of R and S. a) (2,5,3) Ob) (4,2,3) Oc) (4,5,6) Od) (1,5,6)