GMDSS operators should routinely focus on the factors affecting propagation in what priority?

Correct Answer: Option A — Distance & time of day, seasonal variations, sunspot cycle, solar flare alerts.

GMDSS operators must prioritize variables based on their immediate impact on signal path reliability. Distance and time of day are the primary determinants for frequency selection, followed by seasonal variations, the 11-year sunspot cycle, and finally, unpredictable solar flare events that can cause sudden ionospheric disturbances or radio blackouts.