What weather condition does the METAR report indicate related to rainfall?

The correct interpretation of the METAR report regarding rainfall is that it indicates rain of unknown intensity ended 16 minutes before the hour. This is based on the specific coding used within METAR reports, where certain abbreviations and timestamps provide critical information about weather conditions.

In a METAR report, details concerning precipitation are often accompanied by a time indicator. When a report indicates that rain ended, it suggests that meteorological conditions have changed, and the visibility and other factors may now be more favorable. The "unknown intensity" means that while the report confirms rain had occurred, it does not specify how heavy or light it was, leaving it open to interpretation based on the observer's experience or other data.

Additionally, knowing that rain has ended can be essential for flight planning, as it may indicate improved conditions and the potential for clearer skies ahead. Thus, understanding how to decode these vital pieces of information in weather reports is crucial for an aircraft dispatcher's effective operation and safety management.

The other options do not provide the specific detail indicated in the question regarding the conclusion of rainfall at a precise time, or they introduce conditions which do not align with the information presented in the METAR regarding the timing and intensity of the precipitation.