According to a study, after a week of high-altitude living, twenty men had slimmed down. The men, middle-aged residents of low-altitude areas, had been taken to a research station at 2, 650 meters (8, 694 feet) above sea level. They had unrestricted access to food and were forbidden vigorous exercise, yet they lost an average of 1. 5 kilograms (3. 3 pounds) during their one-week stay. Clearly, the lower availability of oxygen at higher altitudes, or hypobaric hypoxia, can be said to have caused the weight loss, since __. Which of the following would, if true, most logically complete the argument?
A: exercise at higher altitudes is more difficult than exercise at lower altitudes is
B: a decrease in oxygen intake has been shown to depress appetite
C: the men all participated in the same kinds of exercise during their stay
D: several weeks after returning home, the men still weighed less than they had before the study
Choose A, B, C or D as your solution.
B