A variety of stimuli can elevate cyclic guanosine monophosphate (cGMP)concentration in smooth muscle,which results in activation of cGMP-dependent signaling pathways in the smooth muscle.This activation typically:

A)Promotes relaxation,partly because of inhibition of myosin phosphatase.
B)Promotes contraction,partly because of decreased endothelin production.
C)Promotes relaxation,partly because of activation of potassium channels .
D)Promotes contraction,partly because of inhibition of InsP3 production.
E)Promotes relaxation,partly because of activation of voltage-gated Ca channels.