<h2>D. If subjects knew they were receiving an active treatment, researchers would not have known if any improvement was due to the new medication or to the expectation of <u>feeling </u>better. If the researchers knew which subjects received which treatments, they might have treated one group of subjects differently from the other group.</h2><h2 />
For your question... the answer would be D
Answer: The axis of symmetry is x=3.
