One Long
Two Long
Three Long
None of these
Answer is Right!
Answer is Wrong!
The correct answer is A. One Long.
The Loco Pilot shall sound one long whistle to acknowledge the Guard hand signal. This is to ensure that both the Loco Pilot and the Guard are on the same page and that the train is ready to depart.
The other options are incorrect because they do not correspond to the correct number of whistles that the Loco Pilot should sound to acknowledge the Guard hand signal.