【单选题】The passage implies that which of the following was true of introductory courses in Asian American studies a few decades ago?
The range of different textbooks that could be assigned for such courses was extremely limited.
The texts assigned as readings in such courses were often not very challenging for students.
Students often complained about the texts assigned to them in such courses.
Such courses were the only means then available by which people in the United States could acquire knowledge of the field.
Few students wanted to take such courses.