a$.$ Imagine a healthcare management system used by clinics to handle patient records, appointment scheduling, and billing processes. Describe how data flows within this system utilizing the Command Query Responsibility Segregation $($CQRS$)$ model $[3+6=9$ Marks$]$

b$.$ Describe how GraphQL can be implemented in the context of healthcare management system described above. Discuss the benefits of using GraphQL for data retrieval across multiple client applications and how it addresses common challenges faced in traditional RESTful APIs. Additionally, outline the steps involved in setting up a GraphQL server and defining schemas to support the platform's data