Patients as Person Accounts, Payment providers as Accounts, & Doctors as Person Accounts is the optimal selection by the data architect to map the actor to Salesforce objects. This is because Person Accounts are a special type of accounts that can store both business and personal information for individual customers. Payment providers are organizations that pay for the care of patients, so they can be modeled as Accounts. Doctors are also individuals who provide care plans for patients and need access to patient information, so they can also be modeled as Person Accounts.