In 1955, legislation in a certain country gave the government increased control over industrial workplace safety conditions. Among the high-risk industries in that country, the likelihood that a worker will suffer a serious injury has decreased since 1955. The legislation, ttherefore, has increased overall worker safety within high-risk industries. Which one of the following, if true, most weakens the argument above? ['Most of the work-related injuries that occurred before 1955 were the result of worker carelessness.', 'The number of work-related injuries occurring within industries not considered high-risk has increased annually since 1955.', 'Because of technological innovation, most workplaces in the high-risk industries do not require as much unprotected interaction between workers and heavy machinery as they did in 1955.', 'Workplace safety conditions in all industries have improved steadily since 1955.']