In One Study on the Effects of Stress, Dental Students

In one study on the effects of stress, dental students received one small puncture wound on the roof of their mouth during their summer vacation and a second wound three days before their first major exam during the fall term. What were the findings of this study?

A) On the average, wounds inflicted during summer vacation took 3 days longer to heal than wounds inflicted just before the major exam.
B) On the average, wounds inflicted just before the major exam took 3 days longer to heal than the wounds inflicted during summer vacation.
C) In both situations, the female dental students healed almost twice as fast as the male dental students.
D) On the average, wounds inflicted just before the summer vacation took 3 days longer to heal than the wounds inflicted just before the major exam.