Consider the following scenario for designing software: A veterinary office is considering having practice management software written for them. They need to be able to track customers and their pets, create appointments for a pet, and create invoices that customers need to pay. Unpaid invoices should be able to be identified. a. [2 points] What classes and data within those classes are needed? Replace this text with your solution b. [2 points] Draw a dependency diagram that shows the relationships between classes identified in part (a) above. Replace this text with your solution