In the Context of Cardiac Nerve Supply,the Sympathetic Nervous System

In the context of cardiac nerve supply,the sympathetic nervous system:

A) decreases the activity of the SA node, the AV node, and the myocardium.
B) releases the neurotransmitter acetylcholine.
C) has little effect on myocardial contraction.
D) becomes active when the body needs to expend energy during the "fight or flight" reaction.