1. Salesforce Architects. (2023). Integration Patterns and Practices. Section: "Batch Data Synchronization". This official guide describes the pattern as ideal for processing records as a group on a scheduled basis, stating, "Data is exported from the source system and imported into the target system in a batch... This pattern is useful when a large number of records need to be transmitted..." This directly matches the scenario.
2. Salesforce Health Cloud Developer Guide. (2024). Health Cloud APIs and Standards. Chapter: "FHIR-Aligned APIs". The documentation details how these APIs are used to create, read, and update specific FHIR resources (e.g., a single patient or encounter). Their design is for transactional, not bulk-extract, purposes, which makes option C unsuitable.
3. MuleSoft Documentation. Batch Processing. As a Salesforce company, MuleSoft's documentation is an authoritative source. It defines batch jobs as the solution for "processing large data sets that can't be processed in a single, real-time transaction," which aligns perfectly with the weekly billing cycle requirement.