Question

max is testing how caffeine affects test scores. what might be a constant in this experiment? the type of test the subjects are taking the subjects favorite foods the eye color of the subjects all of these

Explanation:

In an experiment testing how caffeine affects test - scores, the type of test should remain the same to accurately measure the impact of caffeine. The subjects' favorite foods and eye - color are irrelevant to the effect of caffeine on test scores and are constants as they don't change the relationship being studied.

Answer:

D. All of these