单项选择题

Questions 17 to 20 are based on the following introduction of American students. You now have 20 seconds to read Questions 17 to 20. In-which respect does the students’ organizations seem to be effective

A.dealing with academic affairs of the university.
B.ensuring that the students observe university regulations.
C.evaluating students’ performance in their study.
D.keeping up the students’ enthusiasm for social activities.