Consider a database that keeps track of the textbooks adoption for courses: - Each textbook has a title, publisher and a unique ISBN number. - Each course has a course name and a unique course reference number (CRN). - The name of the department that offers a course should be recorded in the database. - A course can adopt more than one book. The same book can be adopted by more than one course. - A textbook can be adopted as a required book or a recommended book for a course. The type of adoption ('required' or 'recommended') should also be recorded in the database. a) Draw the E-R diagram for the above database. b) Convert the above E-R diagram to a relational database schema