Consider the domain model class diagram shown in Figure 4-16—the refined diagram showing course enrollment with an association class. Does this model allow a student to enroll in more than one-course section at a time? Does the model allow a course section to contain more than one student? Does the model allow a student to enroll in several sections of the same course and get a grade for each enrollment? Does the model store information about all grades earned by all students in all sections?