4. [20 Points) A university database needs to store information about professors (identified by p_id, with title, office, and phone as attributes), departments (identified by d_id, with d_name, and building as attributes), and children (with c_name and age as attributes). Every professor works in only one department; every department is managed by only one professor; the children of the same professor can be distinguished by their c_name (assuming only one parent of a child works for the university). We do not maintain the information of a child once his/her parent leaves the university. Draw an ER Diagram for the university database application described above