单项选择题
A.B.C.D.
A.∀x(O(x)→∀y(P(y)→¬D(x)))B.∀x(O(x)→∃y(P(y)∧¬D(x)))C.∃x(O(x)∧∃y(P(y)∧¬D(x)))D.∃x(O(x)→∀y(P(y)→¬D(x)))