A School's office of the registrar maintains data about the following entities:
a) courses (including course number, title, credits, syllabus and prerequisites),
b) course offerings (including course number, year, semester, section number, instructor(s), scheduled times and classroom),
c) students (including student id#, name and major), and d) instructors (including id #, name, department and title).
Further, the enrollment of students in courses and grades awarded to students in each course they are enrolled for must be appropriately modeled.
Construct an E/R diagram for the registrar's office. Justify all assumptions you made that were not specified above.