An Islamabad based petrol supply company needs to update their automated Billing System to incorporate computation of discounts. The system will be used at their five different petrol stations across the city. Each petrol station provides services (e.g., filling, cleaning, repair, and maintenance) and also has a small shop at the premises to sell different vehicle care products (e.g., engine oil, filters, spare parts, and accessories). The company offers 3 types of memberships: Diamond, Gold and Silver. Diamond, Gold and Silver members receive a discount of 15%, 10 %, and 5%, respectively, for all services provided. Customers without membership receive no discount. Moreover, all members receive a flat 10% discount on products purchased. The discount system will compute the total discount for products and services of a customer's visit. It will read customer's membership information, total amount of services used, total amount of products bought and then compute discount for each customer's bill accordingly. Note that only discount computation is required. Bill generation is NOT required. For example if a customer is a Diamond member and has spent Rs. 4000 for services and Rs. 1000 for products then total discount will be Rs. 700 (15% of Rs. 4000 = Rs. 600 plus 10% of Rs. 1000 = Rs. 100). A. Design an object oriented discount system in C++ consisting of three classes: Customer, Discount and Visit. B. Draw a UML class diagram to represent relationship between these classes. C. Write a driver program to test all the classes. D. You can get the required data form the user or read from a text file. E. Submit UML diagram (compiler generated), complete program source code, and screen shots of sample program outputs.