Mehran has heard from some of his team-mates 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 team-mates 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 team-mates who are given only small amounts of a protein drink.
b) randomly selected team-mates who are given a placebo instead of a protein drink.
c) volunteers from the general campus population who are not given any protein drink.
d) volunteers from the general campus population who begin football training and are given a protein drink.
e) volunteers from the football team who agree to take a placebo instead of a protein drink.

Placebo has a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment.These person's given Placebo will tend to improve their muscle mass. Comparing yourself with them would tends to show you which opinion is more viable.