In which of the following cases would an observational study be preferable to a traditional experiment?

A) A researcher wants to know whether a new drug works better than a standard treatment.
B) A researcher is curious whether strawberry or chocolate ice cream tends to improve mood more.
C) A researcher wants to know whether men are more likely than women to run red lights.
D) Observational studies are preferable to experiments in all of the above cases.

In this scenario, it would be unethical and possibly illegal to create a controlled experiment where men and women are told to run red lights. Therefore, an observational study would be more appropriate to simply observe and record behavior without any intervention. In options A and B, experiments would be more appropriate because the researcher is attempting to compare two treatments (drug vs. standard treatment) and measure whether one factor (ice cream flavor) has an effect on mood. Option D is incorrect because observational studies and experiments both have their own strengths and weaknesses, and there is no one-size-fits-all approach to research.