Q5: (7.5Marks) Consider Cafeteria of SZABIST, where the students can purchase the available items. Cafeteria has their promotions/ discount schemes going on throughout the year. These schemes have direct effect on the billing strategy of this cafeteria. To mention, caf has different discount percentage on lunch item as compared to the refreshments items i.e. 10% and (10%+300) discount on total billing amount respectively (assuming these are the only two types of product that are available at the moment). Define the appropriate class for the cafe along with the derived classes implementing the concept of pure virtual functions in order to calculate the bill of the purchased product. Keep in mind that different bills will be generated for lunch items and for refreshment items