How many threshold stripes are present on a runway that is 23 m wide?

In the context of runway markings, particularly threshold stripes, the number of stripes is determined by the width of the runway. For a runway that is 23 meters wide, the standard practice involves a specific formula for calculating the number of threshold stripes.

The International Civil Aviation Organization (ICAO) recommends that threshold stripes should be installed at specific intervals based on runway width. The guidelines state that for runways that are 23 meters wide, there should be a set number of stripes that align with visual guidance for pilots during landings. Each stripe typically has a width of 1.5 meters, and the full set of markings extends across the width of the runway while providing a clear visual indication of the runway threshold.

In this case, a runway of 23 meters would typically require 6 stripes to conform with these regulations, creating a consistent and recognizable marking for pilots. The count of stripes provides not only guidance but also aids in the safety of aircraft operations during landing and takeoff.

Therefore, selecting the option of 6 is accurate, as it aligns with the ICAO's recommendations for runway marking widths and configurations, specifically for a runway of 23 meters.