A software system for managing restaurant services: There are three kinds of humans involved in this scenario: Waiters, Chefs, and Customers. Each waiter uses a wireless handheld device to communicate with the chefs. Waiters enter Customer orders and receive notices that orders are ready through their handheld devices. The Use Case PlaceOrder Initiated by Waiter. Waiter activates the PlaceOrder option on his handheld device, which brings up an order form on the handheld's display. Waiter fills in the table number for the order. As Customer tells Waiter what she wants to order, Waiter taps on items on order form. If the Customer has special preparation instructions for an item, Waiter selects the CustomizeOrder option and enters the special instructions. When Customer is finished placing order Waiter submits the order to the Chef. The sent order contains the table number, the Waiter's ID code, the items ordered, and all special instructions. The order appears on the Chef's display. After the Chef has prepared the order, he selects the InformOrderReady option. The Waiter's handheld device flashes a message informing him that the order is ready. The Waiter delivers the food to the Customer, then uses the handheld device to record that the order has been delivered. a. Draw a use case diagram for the above scenario. b. Draw Activity diagram for the previous scenario.