If S = {1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {1, 3, 5, 7}, B = {6, 7, 8, 9}, C = {2, 4, 8}, And D = {1, 5, 9}, list the elements of the subsets of S corresponding to the following events:
(a) A ∩ B;
(b) (A ∩ B) ∩ C;
(c) B ∪ C;
(d) (B ∪ C) ∩ D;
(e) A ∩ C;
(f) (A ∩ C) ∩ D.