OG10-156题求助~谢谢~

lepus0107

10th OG第156题：
156.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. Therefore, 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 strengthen the conclusion above?
(A) Company P manufactures products that are more hazardous for workers to produce than does Company O.
(B) Company P holds more safety inspections than does Company O.
(C) Company P maintains a more modern infirmary than does Company O.
(D) Company O paid more for new job-related medical claims than did Company P.
(E) Company P provides more types of health-care benefits than does Company O.

我不太明白的一点是，既然要加强的是对O、P两公司员工的likelihood to have job-related accidents的比较关系，应该从员工自身去考虑，排除那些可能导致在O公司员工更likely to have的情况下却使其实际结果显得比P少have的他因，比如B（P已经在safety上更努力了，但结果还是不如O，说明O公司员工确实less likely to have）。A选项说P员工做更Hazardous的工作，这就导致了员工likelihood to have accidents的不可比，怎么会是对的呢？
求大神解惑，不胜感激~