4.3. A vending machine offers four beverage options: Coke, Fanta, Pepsi, and Soda Water. Customers can purchase multiple drinks if they choose. The vending machine prompts the user to select their desired beverages. After selection, the machine calculates the total price for the drinks and requests payment from the user. They payment be made using bank debit or credit card or MYZAKA or Orange Money. Once the payment is provided, the vending machine dispenses the selected drinks. c) Create a functional model for this system. [5 marks] d) Create a structural model for this system [5 marks]