The correct option is D ANS
The autonomous nervous system control the heart beat rate via cardio regulatory centre in medulla oblongata. The emergency conditions activate the sympathetic motor nerve and make the adrenal medulla to release epinephrine and nor-epinephrine which in turn increase the heart beat rate. Thus, the correct answer is C. The central nervous system (Central NS) includes brain and spinal cord. It integrates and stores the sensory information from external and internal sense organs and commands different organs to respond accordingly. Peripheral nervous system (PNS) lies outside the central nervous system and is further divided into somatic and autonomic nervous system. It serves to carry the sensory information from external sensory receptors to CNS and motor signals from CNS to skeletal muscles via its somatic division (the voluntary actions). The autonomic division of peripheral nervous system controls the cardiac and smooth muscles and glands, thereby the functioning of internal organs, without our conscious control (the involuntary actions). On the other hand, vagus nerve conducts the parasympathetic motor impulses which in turn slow down the hearth beat rate by effect of acetylcholine; a neurotransmitter released by parasympathetic nervous system.