下列四个公式正确的有（）
A. $\forall x(A(x) \wedge B(x)) \Longrightarrow \forall x A(x) \wedge \forall x B(x)$
B. $\forall x(A(x) \vee B(x)) \Longrightarrow \forall x A(x) \vee \forall x B(x)$
C. $\exists x(A(x) \vee B(x)) \Longrightarrow \exists x A(x) \vee \exists x B(x)$
D. $\exists x A(x) \wedge \exists x B(x) \Longrightarrow \exists x(A(x) \wedge B(x))$