$($b$)$ A software system to allow student self$-$registration is to be developed. The

system will be limited to students registering for their second and

subsequent years only, so it can be assumed the students will already have a

student ID and programme.

To register, students first confirm their programme and year and then

confirm the modules they will be taking. Module choices can be restricted in

a number of ways: there is usually a specified number of modules to be

taken of which some subset are mandatory while others may be chosen from

a pool of options; modules may specify prerequisite modules that must have

been passed already; and finally, certain module combinations may be

prevented because of timetabling clashes. The timetable specifies how

modules are scheduled to time slots in lecture rooms across the university.

Document the domain model for this system $($about $4-6$ classes with

appropriate attributes and associations$).$