Please help this question male rats were treated with caffeine for 7 days and?

measured the locomotor activity of the rats each day. 3 days after treatment had finished they accessed the strength of binding of dopamine to d2 receptors, in rats brains. A separate group of rats was treated with distilled water for 7days and same measurements were made. state the independent variable and its conditions, the two dependant variables and control of the study. thank you