题目选项分析

During periods when a large number of patients are admitted to a hospital, more qualified nurses are hired and more money is spent on nurse training than when the number of patients in a hospital is low. Thus, the average number of mistakes made by nurses should be lower during periods when there is a large number of patients in a hospital than when there is a small number of patients in a hospital and less money is available to hire qualified nurses and provide training to all nurses.

Which of the following, if true about a hospital during a period in which a large number of patients are admitted, casts the most serious doubt on the conclusion drawn above?

【选项】Its training program for nurses is very rigorous.