The new software organization requires a new point of sale and stock control system for their many stores throughout Pakistan to replace their aging mini-based systems. A sales assistant will be able to process an order by entering product numbers and required quantities into the system. The system will display a description, price, and available stock. In-stock products will normally be collected immediately by the customer from the store but may be selected for delivery to the customer's home address for which there will be a charge. If stock is not available, the sales assistant will be able to create a backorder for the product from a regional warehouse. The products will then either be delivered directly from the regional warehouse to the customer's home address, or the store for collection by the customer. The system will allow products to be paid for by cash or credit card. Credit card transactions will be validated via an online card transaction system. The system will produce a receipt. Order details for in-stock products will be printed in the warehouse including the bin reference, quantity, product number, and description. These will be collected by the sales assistant and given to the customer. The sales assistant will be able to make refunds, provided a valid receipt is produced. The sales assistant will also be able to check stock and pricing without creating an order and progress orders that have been created for delivery.
You need to answer the following questions. (Marks 8)
1. Design a detailed Domain model for the Sale and Stock Control system.

2. List down classes and abstract classes in the above system.
3. Give any one scenario of inheritance of classes.