Answer:D
Step-by-step explanation:
The ANS helps to maintain homeostasis (internal stability and balance) through the coordination of various activities such as hormone secretion, circulation, respiration, digestion and excretion. The ANS is always "on" and functioning unconsciously, so we are unaware of the important tasks it is performing every waking (and sleeping) minute of every day.
acetylcholine is the primary neurotransmitter of the PNS. Acetylcholine acts on cholinergic receptors known as muscarinic and nicotinic receptors. Muscarinic receptors exert their effect on the heart.