Design ER model specifying key attributes, entity types, relationship types (1: 1, 1: N, M: N), and structural constraints (partial or total participations). Make your assumptions and state them (if any). Choose appropriate attributes if not given as part of the requirement analysis. Consider the following requirements for a University Accommodation Office: (a) Each hall of residence has a name, number, address, telephone number and a hall manager who supervises the operation of the hall. The halls provide only single rooms which have a room number, place number and weekly rent rate. The total number of rooms provided by the accommodation office should be able to be computed on the fly. (b) The place number uniquely identifies each room in all of the halls controlled by the accommodation office and is used when renting a room to a student. (c) Students may rent rooms throughout the academic year for various periods of time. Each individual rent agreement between a student and the accommodation office is uniquely identified using a lease number. The data regarding rooms currently rented include the lease number, date that the students started rent period and date that the student wishes to terminate the rent period (if known). (d) Information regarding an undergraduate student includes: student ID, name (first, middle, last), home address (street, city, state, zipcode), date of birth, category of student (e. g. freshman, sophomore). (e) The total number of students living in each hall should be able to be computed. (f) Information about a student's emergency contact is stored, including name, relationship, address, and contact number.