Which of the following best describes varied visibility in a METAR report?

The correct answer focuses on the concept of varied visibility reflecting changing weather conditions. In a METAR report, varied visibility is often indicative of fluctuating factors like precipitation, fog, or differences in air quality that can cause visibility to change over time. When visibility is reported as varied, it suggests that the pilot or observer may experience different conditions as they move through the reporting area. This can lead to critical considerations for flight operations, where a sudden change in visibility could affect safety.

Other choices do not accurately capture the essence of varied visibility. Visibility reported as a constant number implies no changes, which contradicts the idea of variability. Strict measurements would indicate a stable level, while unchanged visibility doesn't allow for dynamic weather scenarios that can affect a pilot's ability to navigate safely. Hence, describing visibility as varying is essential for understanding how fluctuations in weather conditions directly influence visibility metrics in aviation contexts.