C-01-Q063mediumsingle_mcqIf A⊂BA \subset BA⊂B, then:aB′⊂A′B' \subset A'B′⊂A′bA′⊂B′A' \subset B'A′⊂B′cA′=B′A' = B'A′=B′d(A∪B)′=∅(A \cup B)' = \emptyset(A∪B)′=∅