According to a recent school survey, the number of students who regularly attend religious services on campus has increased 50 percent from the figure 10 years ago. It must be an increased spirituality at our college that has massively reduced incidences of cheating on exams during this period.
Which of the following, if true, most significantly weakens the inference above?
A. Most of the students who now attend campus services do so largely for social reasons.
B. Spirituality can be expressed and felt without attendance at regular religious services.
C. Fifteen years ago, the college switched from an honor system to one involving closely monitored faculty-proctored exams.
D. Not all students who attend religious services regularly on campus responded to the survey.
E. Cheating has not been a major problem at this school in the past.