The scenario below describes the use case for the sale of films at the FilmsCompany using its online system. A client can either browse films by category (e.g. action, romantic, drama etc) or search films by typing any specific film detail in the search field. Other details stored about the films are an id, title, star cast, price and number of copies. FilmsCompany has many copies of a film each having a unique copy number. The system then displays a list of films that matches the search criteria or category. The client then selects his/her film(s) and the system calculates and displays the total price. The client is offered a 10% discount if the number of films exceeds three. The client can either confirm his selection or can go back to browse/search more films or he can exit the system. The client then either logins into the system with his username and password or registers with the system with his name, address, a username and a password. The system validates the information entered and reverts back to the client in case of errors. After successful validation, the system moves to another screen where the client enters his/her payment details (credit card number and pin code) to proceed with the actual payment. The system validates the credit card number and pin code combination. The system allows a client to enter his/her payment details a maximum number of 3 times whereby the system automatically exits if wrong payment details have been entered more than 3 times. The corresponding funds are transferred to the companys account and the system confirms the sale by issuing a sale reference. This reference is saved by the client for onwards presentation upon receipt of the films by Ricardo, the despatcher. In order to cater for copyright infringement, it is necessary for the system to monitor the existing association between a film copy and a client. By making suitable assumptions, if any:

(a) Draw an activity diagram to illustrate the sale process at the FilmsCompany. (b) Draw a class diagram for the above system. (c) Draw a sequence diagram showing the basic interactions of the client with the FilmsCompany system.