Respuesta :
Answer : Option B) The study does not include a control group.
Explanation : The experiment does not includes a control group in it, as the inclusion of control group would have been used as a benchmark to measure how the other tested results were. The biologist simply hypothesized that restricting food from mice will decrease their activity. And on the same he designed his experiment in which he observed the activity of 50 mice under restricted food regimens. And he lacked a comparison for the results, i.e the control group.