Under what conditions is the arrector pili muscle stimulated? what part of the brain would produce an efferent signal to this smooth muscle effector?

The pili arrector muscle, or erector muscle of the hair, is a muscle composed of smooth muscle fibers which is innervated by the sympathetic nervous system (SNS). When the hair is erect, what is known as "goosebumps" is produced; This action is involuntary and can be caused by fear, cold, among others. The efferent signals to activate this muscle come from the hypothalamus, brain stem and spinal cord.

A. They will be repelled because they are in each other's magnetic

field.

Explanation: Apex and gravity and electrical don't have effect on magnets magnetic field.