Mehran has heard from some of his teammates that drinking a high protein supplement after football training will improve his muscle mass. He decides to test this hypothesis by examining the effect of a high protein drink on some of his teammates compared with what happens with a control group who drink only water. Which of the following would be the best control for his experiment? a. randomly selected teammates who are given only small amounts of a protein drink
b. volunteers from the general campus population who begin football training and are given a
protein drink
c. volunteers from the general campus population who are not given any protein drink
d. randomly selected teammates in training who are given a placebo instead of a protein drink