Immediately before starting the maneuver.✓Правильный ответ
Immediately after completion of the maneuver.
During the execution of the maneuver.
Объяснение
A hand warning is withdrawn just before the vehicle starts the intended movement, because keeping an arm extended throughout the maneuver may be impractical and unsafe. Ending it only after completion would confuse the hand-signal rule with the rule for an electric direction indicator.