Question

Derrick just got home from playing soccer on a muddy field. He is curious how different brands of laundry detergent compare in removing mud from clothes, so he sets up an experiment. In one laundry load, he puts his muddy socks with Brand A detergent. In the next load, he puts his muddy jersey with Brand B detergent. In the final load, he puts his muddy shorts with Brand C detergent.
Afterward, he noticed that the jersey came out the cleanest. He concludes that Brand B is the best detergent for removing mud from clothes. Is his conclusion valid?
No; Derrick was biased toward Brand B.
Yes;