A dog owner wants to test how exercise affects how his dog sleeps. On day 1, he exercises his dog for 2 hours and then records the amount of sleep the dog experiences that evening. The next day he exercises the dog for 4 hours and records the amount of sleep experienced by the dog and finally he records the amount of sleep with 6 hours of exercise. He was careful to give his dog the same amount of food on the days he did the experiment.

Independent Variable - Hours of Exercise

Dependent Variable - Hours of Sleep

Control - Food

Explanation:

In an experiment, there are two variables independent variable and dependent variable. The independent variable is defined as the variable that can be changed or manipulated while the dependent variable is defined as the variable that is measured as an effect of the independent variable. Constant is a value in an experiment that does not change.

In the given example, hours of exercise  is the independent variable because it is changing every day, and hours of sleep  is the dependent variable because it is the measurable effect or outcome in which the dog owner is interested. Food is constant because the dog is getting the same amount of food on the days of the experiment.

Hence, the correct answer is "Independent Variable - Hours of Exercise

Dependent Variable - Hours of Sleep

Control - Food".

the answer would be c