C-01-Q107mediumsingle_mcq(A∪B∪C)′=?(A \cup B \cup C)' = ?(A∪B∪C)′=?aA′∩B′∩C′A' \cap B' \cap C'A′∩B′∩C′bA′∪B′∪C′A' \cup B' \cup C'A′∪B′∪C′cA∩B∩CA \cap B \cap CA∩B∩CdA′∩B∩CA' \cap B \cap CA′∩B∩C