What Is Life? 2nd Edition by Jay Phelan

Exercise 14

In a recent study, patients treated with a genetically engineered heart drug were able to walk on a treadmill 26 seconds longer than those not receiving the drug, and they showed no side effects from taking the drug. Can we conclude that this drug is an effective treatment for heart disease?
A) No. Genetically engineered drugs cannot be tested by the scientific method; they require comparative observations.
B) No. It is not clear how many subjects were in the study.
C) No. It is not clear that the drug is not a placebo.
D) Yes.
E) No. It is not clear that the proper controls were included.