单选题 When cut, the synthetic material fiberglass, like asbestos, releases microscopic fibers into the air. It is known that people who inhale asbestos fibers suffer impairment of lung function. A study of 300 factory workers who regularly cut fiberglass showed that their lung capacity is, on average, only 90 percent of that of a comparable group of people who do not cut fiberglass.
The statements above, if tree, most strongly support which of the following hypotheses?
【正确答案】 B
【答案解析】