Answer Happy

Please I need help with this for better understanding andclarity. Thank you
Threat Modelling As a group of security experts, you are to perform security analysis of a software company that provides a mobile app for accessing health services including requesting for lab tests to be done, booking appointments with specialty doctors and buying medicine. The system as two parts: the mobile app for customers to request for services and a web app for doctors, lab technicians and pharmacists to manage requests. Payment for the services are made through the mobile application. A third-party company handles all payments and gives the money to the software company daily.
3. Identify your security requirements: What security objectives are most important for the system and why? List objectives in order of preferred importance. 4. What security approach will be most effective for this system: Technology and cost tradeoff. Explain why.