Explain how versioning of messages helps maintain backward compatibility in the EPD Pilot.

• A. It increases encryption strength with each version.
• B. It enforces fixed routing paths regardless of version.
• C. It allows newer endpoints to communicate with older ones by including version fields and supporting multiple message formats.
• D. It eliminates the need for testing new features.

Answer: (C)

Versioning in messages keeps backward compatibility by tagging each payload with a version number and supporting multiple formats. The version field tells the receiver how to interpret the data, so an endpoint designed for an older schema can still parse messages from newer endpoints, and vice versa. When a newer endpoint sends a message with extra fields, the older endpoint can ignore the unfamiliar parts or a translator can map them to the older format. This lets components evolve independently without breaking communication in the EPD Pilot. The other ideas don’t address how different versions are understood by different endpoints, and they miss the core mechanism: compatibility comes from clearly signaling the version and supporting multiple formats.