(a) (b) (c) In developing a Video Rental System for a local video store, the owner of the store suggests using a customer's home telephone number as the identifier for its customers. Explain if you agree or disagree with the owner's suggestion. (6 marks) The business rules expressed in the following ERD fragment are "A staff member must man age one or more other staff members" and "A staff member must be managed by an other staff member". Is there anything wrong with the business rules? Explain why or why not. STAFF manages is managed by (4 marks) Using examples of entity sets and entity instances, clearly explain, with the help of a diagram, a relationship that a computer may (optional) be assigned to one staff member and a staff member may only be assigned at most one computer. You need to show the different scenarios possible in your diagram (4marks)