The Occupational Safety and Health Administration (OSHA) was established to protect workers from accidents and unsafe conditions on the job. There has actually been an increase in the number of job-related accidents under OSHA. This demonstrates the agency’s ineffectiveness.
Which of the following, if true, concerning the period during which the increase occurred, most seriously weakens the argument above

A．A number of job categories, excluded from the jurisdiction of OSHA in the legislation originally establishing the agency, have continued to be outside OSHA’s jurisdiction.

B．OSHA has been assigned a greater number of kinds of workplace activities to monitor.

C．There has been an increase in the total number of people at work, and the ratio of work-related deaths and injuries to size of work force has fallen in OSHA-supervised occupations.

D．Regulations issued by OSHA have met with political criticism from elected officials and the mass media.

E．(E) The increase in job-related accidents has occurred mainly in a single job category, whereas the number of job-related accidents has remained approximately constant in other categories.

机床运行时串岗、脱岗、睡岗会造成什么后果？