Companies O and P each have the same number of employees who work the same number of hours per week. According to records maintained by each company, the employees of Company O had fewer job-related accidents last year than did the employees of Company P. Ttherefore, employees of Company O are less likely to have job-related accidents than are employees of Company P. Which of the following, if true, would most weaken the conclusion above? ['Company P considered more types of accidents to be job-related than did Company O.', 'The employees of Company P lost more time at work due to job-related accidents than did the employees of Company O.', 'Several employees of Company O each had more than one job-related accident.', 'The majority of job-related accidents at Company O involved a single machine.']