Mei wanted to see if a new toy model car would sell better in blue or in red among children. She went to a college campus and on Sunday she showed 50 college students the model car in red and Monday she showed 50 college students the model car in blue. After showing them the car, she asked each college student to rate how much they liked the brand of the toy model car. Mei did not conduct a good experiment because a. she sampled the wrong population b. she asked the wrong outcome question c. she added a third variable by asking on different days d. both B&C e. both A&C