Which of the following is NOT an example of responding to stimuli? A. Pulling your hand away from something hot. B. Maintaining internal pH levels. C. Stopping at a red light. D. Plants growing towards light.

Johnny rode his bike 4 blicks down the street to his friend's house once he got to his friend house and realized he could not cone out to play he turned aroubd and went back home.what is displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point