When is a pilot expected to commence a sidestep maneuver?

A sidestep maneuver is typically initiated when the pilot has the runway environment in sight, indicating that they can visually identify the runway for which they are cleared. This maneuver allows the pilot to position the aircraft laterally to align with a runway that is adjacent to the one they were originally approaching. The visibility of the runway environment ensures that the pilot can make an informed decision to execute the sidestep safely.

Commencing this maneuver relies on the pilot's ability to clearly see the designated runway, which is critical for maintaining situational awareness and ensuring that there is adequate distance to align with the new runway safely. This makes it the appropriate time to begin the sidestep maneuver. Other options do not align with the required visual confirmation needed for safe flight operations.