All academic departments in a University keeps a database of its students. Students are classified into undergraduate, graduate, and international students. There are few reasons for grouping the students into these three categories. For example the department's secretary informs: the undergraduate students about new undergraduate courses offered, the graduate students about graduate courses and professional conferences and international students about new emigration laws.
i. Identify (if any) the subtypes of entity students.
ii. Identify a unique attribute (relationship) for each subtype.
iii. Draw an EER diagram for the department's database.​