Valley Hospital is trying to reduce the number of hospital-based infections that are occurring. Its director of training has determined that a training program to encourage all employees who have contact with patients to wash their hands frequently would be effective in reducing infections. The most appropriate criterion of success for this training program would be: a. the number of times the hospital staff wash their hands per day in the year following the training. b. the percentage of hospital staff who respond on a follow-up questionnaire that hand washing is important in reducing hospital-based infections. c. the cost per staff member of the training program. d. the death rates (mortality) of patients in the hospital