41. 已知二個關聯(relation) R(a, b)={(0, 1), (0, 2), (2, 4), (3, 4)},S(b, c)={(1, 2), (2, 0), (2, 3)},則 R 與 S 的自然合併(natural join),R S= (A) {(0, 1, 2), (0, 2, 0), (0, 2, 3)} (B) {(1, 2, 1), (2, 0, 2), (2, 3, 4)} (C) {(0, 1, 2), (0, 2, 0), (2, 4, 3), (3, 4, 3)} (D) {(1, 2, 4), (2, 0, 1), (2, 0, 2), (2, 3, 4)}