Which type of visibility is reported in the body of weather observations?

The reason prevailing visibility is the correct choice is that it refers specifically to the greatest horizontal distance range at which objects can be clearly seen and identified in the direction of the prevailing conditions. In aviation weather reports, prevailing visibility is a standard measurement because it provides pilots and flight operations personnel with critical information regarding how far they can see in the airspace they will be operating. This is especially important for safe takeoffs and landings.

Other types of visibility, such as horizontal visibility, can be less precise in certain contexts and may not reflect the conditions prevalent in a specific direction, while vertical visibility focuses on how far one can see upward (typically in overcast conditions). Maximum visibility is also not a standard term used in aviation weather reporting. The emphasis on prevailing visibility is due to its practicality in flight safety, as it represents the most relevant visibility condition affecting flight operations.