Indicate whether the study is an observational study or a controlled experiment. Patients with multiple sclerosis are randomly assigned a new drug or placebo and are then given a test of coordination after six months. Question content area bottom Part 1 Choose the correct answer below. A. This is an observational study because the patients were assigned drugs by those conducting the study. B. This is an observational study because the patients chose whether they took the drug or the placebo. C. This is a controlled experiment because the patients were assigned drugs by those conducting the study. D. This is a controlled experiment because the patients chose whether they took the drug or the placebo