Draw use case and sequence diagram.

Gas Station: Assume that there exist at least the following three classes: Person, Pump, and PayStation. Additional classes may be introduced to clarify the interaction. a- Draw a use case diagram for the functionality of a single gas pump at a gas station. Assume that a credit or debit card may be used at the pump, as well as pay cash inside the gas station. Cash may only be used inside of the station. There are three brands of gasoline: low grade, mid grade, and high grade. b- Draw a sequence diagram for the following scenario: A customer pulls into the gas station to fill up at the gas pump. The customer presses the "pay by credit" button, and fills his tank with low grade and mid grade gasoline (Assume switching from one grade of gasoline to another is a trivial operation). At the end of filling the gas tank the total charge is displayed at the pump, and the customer is asked to swipe his credit card. Realizing that he mistakenly left his credit card at home, the customer proceeds to pay inside the gas station with cash. c- Draw the CRC for each class and the dependency relations between classes