根据学生所说内容 “My chair person told me that if I did independent field research in addition to the assigned work in each course; they would count as intermediate level courses. My classmates, um, some of my classmates, did this for an easy way to meet their intermediate course requirement, but I did it to get the kind of depth in those topics I was going for.” 可知，由于学生想修的课题没有中级的课程，所以系主任建议学生选择做独立的实地研究，可以算作中级课程的学分。后来有些同学就选择了简单的方式，他们只是为了拿到中级课程的学分。而学生则对自己所选的课题进行了深入研究。所以可以推测学生将自己与同学的学习动机进行了对比，强调自己的学习动机和有些同学不一样。选项 D 正确。

答案: D