According to a small-scale study, people who are thinner don't necessarily eat better or exercise more than others, they just get up early and get a little more sun. Dawn has an impact on the body mass index of about 20%. The sooner the sun goes, the lower the body mass index, and vice versa. Therefore, the researchers proposed that if you want to lose weight, you only need to get up early to take a sun. Which of the following, if true, best illustrates the failure of the above findings? ['Farmers in some areas have been thin and hard every day.', 'There is plenty of light in a beach resort, but the locals are fat.', 'Compared to those who adhere to indoor fitness, the weight change of the jogger facing the dawn is relatively small.', 'A university called for students to do morning exercises, and the classmates who insisted on tanning a lot, but did not lose weight.']