Mark Is a Participant in a Human Intervention Study That

Multiple Choice

Mark is a participant in a human intervention study that is testing the impact of selenium supplements on the performance of endurance athletes. Though Mark does not know if he is receiving selenium or an inactive sugar pill, he is sure that it is the tablet that he is taking that has helped him shave several minutes off his usual marathon time. What effect is Mark experiencing?

A) Thornburg
B) Placebo
C) Predisposition
D) Hawthorne