SYMPATHETIC
D) sympathetic.
The sympathetic nervous system is a division of the autonomic nervous system that is responsible for preparing the body for "fight or flight" in response to stress or danger.
The sympathetic nervous system activates the "stress response," which involves a series of physiological changes that help the body respond to a perceived threat.
One of the functions of the sympathetic nervous system is to stimulate the arrector pili muscles, which are small muscles attached to the base of hair follicles. When the arrector pili muscles contract, they cause the hair to stand on end, giving you "goosebumps." This is an evolutionary response that helped animals appear larger and more intimidating when confronted with a threat.
The other options in the question are not related to the sympathetic nervous system or the arrector pili muscles.
The parasympathetic nervous system is the other division of the autonomic nervous system and is responsible for promoting relaxation and rest.
Afferent neurons are sensory neurons that transmit information from the body to the central nervous system.
The dorsal column refers to a group of nerve fibers in the spinal cord that carry sensory information to the brain.
The somatic nervous system is the division of the peripheral nervous system that controls voluntary movement and sensory information from the body.
