According to a school survey conducted last month, the number of stude

According to a school survey conducted last month, the number of students who regularly attend religious services on campus has increased fifty percent from the figure ten years ago. It must be this increased religiosity at our college that has led to a recent, massive reduction of incidences of cheating on exams.

Which of the following, if true, most significantly weakens the inference above?

(A) Most of the students who now attend campus services do so only for social reasons.
(B) Campus chaplains have time and again spoken about the importance of academic honesty.
(C) Fifteen years ago, the college switched from an honor system to faculty-proctored exams.
(D) Only freshmen and sophomores responded to the survey.
(E) Cheating was never a major problem at this school.