Asbestos, an almost indestructible mineral once installed as building insulation, poses no health risk unless the asbestos is disturbed and asbestos fibers are released into the environment. Since removing asbestos from buildings disturbs it, thereby releasing asbestos fibers, the government should not require removal of all asbestos insulation. Which one of the following, if true, most strengthens the argument? ['Some kinds of asbestos, when disturbed, pose greater health risks than do other kinds.', 'Much of the time, removed asbestos is buried in landfills and forgotten, with no guarantee that it will not be disturbed again.', 'Asbestos can pose a health threat to workers who remove it without wearing required protective gear.', 'Asbestos poses far less risk to health than does smoking, drug and alcohol abuse, improper diet, or lack of exercise.']