单项选择题

Normally a student should attend a certain number of classes to graduate, and each lesson which he attends offers him a credit (学分) which he may count towards a degree. In a lot of American universities the total work for a degree consists of six courses each lasting for one term. A typical course consists of four classes per week; normally a student would expect to take four years attending two terms each year. It is possible to spread the period of work for the degree over a longer period. It is also possible for a student to move between one university and another during his degree course, though this is not in fact done as a regular practice.
For each course that follows a student is given a grade, which is recorded, and the record is available for the student to show to prospective employers. All this imposes a sustainable pressure and strain of work, but despite of this, a few students still find time for great activity in student affairs. Elections to positions in student organization arouse much enthusiasm. The effective work of maintaining discipline is often performed by students who advise the academic authorities. Any student who is thought to have broken the regulations, for instance, by cheating has to appear before a student court. With a great number of students, the operation of the system does involve a certain number of activities. A student who has held one of these positions of authority is much respected and it will be beneficial to him later in his career.

Some students are enthusiastic for positions in student organizations probably because()

A. they hate the constant pressure and strain of their study
B. they will then be able to stay longer in the university
C. such positions help them get better jobs
D. such positions are often well paid