Answer:
D
Explanation:
A, B, and C, are all observing the situations, while D states the deer walked down the path earlier because of the tracks, this is hardly obersavable, and you would have to infere the deer took the path early.
Answer:
It is a group designed to not be affected by any variables and to be used as a comparison to the other groups. It helps increase the reliability of your results, as it shows your independent variable is what made something happen in your experiment.
Newtons second law...........................