Question ID:PT81 S2 Q22 Passage:In a recent study, one group of participants watched video recordings of themselves running on treadmills, and a second group watched recordings of other people running on treadmills. When contacted later, participants in the first group reported exercising, on average, 1 hour longer each day than did the other participants. This shows that watching a recording of yourself exercising can motivate you to exercise more. Stem:Which one of the following, if true, most weakens the argument? Correct Answer Choice:DChoice A:In another study, people who watched recordings of themselves lifting weights exercised for more time each day than did people who watched recordings of themselves running. Choice B:Another study's members exhibited an increased willingness to give to charity after hearing stories in which people with whom they identified did so. Choice C:Participants who were already highly motivated to exercise did not report exercising for any longer each day than they had before the study. Choice D:In studies of identical twins, participants who observed their twin reading overreported by a significant amount how much time they themselves spent reading in the days that followed. Choice E:A third group of participants who watched recordings of themselves sitting on couches afterwards reported being sedentary for more time each day than did the other participants.