Question

which of the following would present the strongest evidence in a commercial promoting a new pain reliever?
testimony of more than three users endorsing the drug
mention of the magazines that have published details of the drug
introduction by a famous doctor who claims the drug works
details of testing conducted by an unbiased group of scientists

Explanation:

Scientific testing by an unbiased group is objective and reliable evidence. User testimonials can be subjective, magazine mentions don't prove efficacy, and a famous - doctor's claim may be influenced by bias.

Answer:

Details of testing conducted by an unbiased group of scientists