Because it creates a common platform or foundation on which a variety of different solutions are implemented, the FHIR spec typically requires further adaptation specifying which four things?

• A. Rules about which resource elements are used and the corresponding elements that are not part of the base specification; which exchange features are used, and how; which terminologies are used in particular elements; descriptions of how the resource elements and API features map to local requirements and/or implementations
• B. Rules about which resource elements are used and the corresponding elements that are not part of the base specification
• C. Which exchange features are used, and how
• D. Which terminologies are used in particular elements

Answer: (A)

The idea here is that to make the broad FHIR standard workable in different settings, a profile or implementation guide narrows and specifies how the base spec is used in a particular context. That adaptation covers four key areas: first, which resource elements are actually used and which base elements are excluded or require changes (and how extensions may fill gaps); second, which exchange features are employed and how they are implemented in practice (for example, which REST operations, search parameters, paging, and interactions are supported); third, which terminologies are bound to specific elements (including which code systems or value sets are used and the strength of those bindings); and fourth, how the resource elements and API features map to local requirements and implementations (clear guidance on how the global standard is realized within a specific organization or setting). This comprehensive framing is why the combined description is the best answer: it captures all four dimensions that ensure interoperability while allowing diverse solutions.