One Criticism of Crum and Langer's Hotel Experiment Was That

One criticism of Crum and Langer's hotel experiment was that:

A) members of the informed group might have engaged in more exercise, eaten healthier foods, and so on, after being told about the benefits of exercise even though they reported no changes in their behavior.
B) there was no control group used in the experiment.
C) because it was not a double-blind, placebo-controlled study, the results are invalid.
D) members of the uninformed or control group might have engaged in more exercise, eaten healthier foods, and so on, after being told about the benefits of exercise even though they reported no changes in their behavior.