GRE Reading Comprehension: Maggoosh-GRE阅读Maggoosh - 2771M4BOR544H01DM

Which of the following is necessary to evaluate the argument? A. The probability that those cyclists admitted to an emergency room have suffered similar accidents in the past B. The durability of bicycle helmets over the course of many years C. The number of riders wearing bicycle helmets compared to the number not wearing helmets D. Whether the bicycling activities of cyclists using a helmet differs from the activities of those not wearing a helmet E. The number of medical staff who are in the emergency room when an injured cyclist arrives