Consider the following scenario for an Online Bus Reservation System application: Consider an online reservation system for a bus company, The bus company includes several buses and realizes trips to different cities. Such bus is identified by its plate color and a separately assigned bus number. The trips are based on a predefined schedule and stop at predefined bus stations. Each bus can have only one trip per day, each bus includes a driver and one hostess. For long trips, the bus will have a break at, service and rest areas, there are two types of trips: normal trips and express trips. Express trips do not stop at intermediate stations and get faster at the destination, Seats can be reserved by customer on the web site of the bus company The customer has the option to directly pay for the seat through the website. In that case, the seat cannot be cancelled (neither by the customer nor by the company). If the customer has not paid for the seat, the bus company can cancel the seat if the customer does not show up one hour before the trip. When the reservation is cancelled, the seat will become free and can be sold to another customer. Both the customer and the company staff must authenticate themselves for performing operations with the system a) Draw the USE CASE Diagram (having at least one "include" and "extend" connection). Mention the purposes of include or extend symbol. [5] b) Write down the USE CASE Descriptive Form for one of a major Use Case. [4] c) Draw Sequence Diagram for the above scenario. [5]