Consider a course registration system for a college. Students are expected to register for the course of study of their choice. Additionally, an administrator at the college does occasionally add new courses to the list of available ones for students to have a wider selection of courses. It is possible for an administrator to cancel a course if it is no longer being offered. A cancelled course might be available at another time. However, when a course becomes unpopular, it is deleted altogether and cannot be reactivated at a later date. A deleted course is permanently removed from the list of courses at the college. An example course of study is BSc in Computer Science. Courses are delivered on a semester basis, with each semester having 4 modules that students must study, a total of 8 modules altogether to complete a year of study. An instructor is assigned up to 4 modules across the different levels of study. Students in levels 4 and 5 have no optional modules; however in level 6, students have two electives and 2 mandatory modules. To proceed between levels, a student must pass half of the modules for the current level. A pass mark constitutes a score of at least 40% on assessed work for the module. Users of the system Students - a student is a key stakeholder of this system as they choose courses, and enroll for modules on that course. At level 6, the student is also able to select from some optional courses during semesters 1 and 2. Students also are able to view which instructor(s) are teaching on the modules they are studying. Course administrator - they can add new courses, add modules to a course, cancel a course, or delete a course altogether. They also are responsible for edits/amendments of course names, module names, etc. An administrator is able to generate a report/result slip for a student depicting modules done for the semester or year of study, and the marks and grades for each module. Based on this, there is a decision appended to the result slip indicating whether a student will progress to the next level of study or not. Instructor - they are assigned modules to teach, can view what modules they are on, and the students registered on those modules. Instructors are able to add marks to each module they are responsible for teaching. Key features required of the system  Ability to amend courses and modules.  Ability to amend instructor details or to remove instructors from modules.  Ability to produce a result slip for each student indicating their grades on each module  Persistence of data - all data is saved between program invocations Additionally, there should be evidence of application of object oriented concepts, such as inheritance, encapsulation, object associations and polymorphism.