An Experiment Is Conducted to Test a New Antianxiety Drug

An experiment is conducted to test a new antianxiety drug.After taking the drug,35 percent of the participants receiving the medication report less anxiety,compared to 36 percent of those taking a placebo.The researchers should conclude that

A) participants knew which group they were in.
B) the medication itself probably has no real effect on anxiety.
C) the placebo is a better medication than the drug.
D) the drug is an effective treatment for anxiety.