Students in Ms. Owen’s class were assigned a task: model some part of the stimulus-response system in the human body. Sarah and Jose used the toy shown in the diagram to model one stimulus-response function of the nervous system. The ball rolls down the top ramp, then drops into the ramp below it and continues to roll.
Which function of the nervous system does the model BEST explain?
A) how the signal from a nerve in the skin reaches the brain
B) how the brain causes a gland to become more or less active
C) how the brain and spinal cord make up the central nervous system
D) how the nerves of the body can act together to produce movements