which structure is at work when the body deals with reflex actions?\no the heart\no the brain stem\no the…

Brief Explanations:

Reflex actions are rapid, involuntary responses. The spinal cord is the main structure involved as it can process and initiate reflexes without the need for the brain to be fully involved in every step. It can receive sensory information, process it, and send motor - responses quickly.

Answer:

D. the spinal cord