Please draw the ERD showing clearly the cardinalities at both ends and the appropriate symbols at both ends of the relationship. Also indicate the primary key and foreign keys of both tables if any. Please resolve M:N relationships to appropriate 1:M relationships. Please show appropriate relationship strength also. Please use any tool available to draw your ERD. Alternatively you can draw it in Microsoft Word or Paint.You may also draw it by neatly by hand, scan and submit. Please note that I will give credit to your submission only if I am able to read your ERD!!!Please indicate if some aspect cannot be implemented in table design and why.a)A professor grades many students and a student is graded by many professors. The university needs to store the grade given to a student by a professor.b)Author writes a book and a book is written by a authorc)A publisher may publish many books and a book may be published by a publisher. The relationship strength has to be weak. Why?d)A building has many rooms and a room is located in a building.