35
30
40
35
Answer is Right!
Answer is Wrong!
The correct answer is: 30 minutes.
The guard of a passenger train shall sign on 30 minutes before the actual departure of the train. This is to ensure that they are ready to board the train and that they have all the necessary paperwork in order. It is also to allow them to check the train and make sure that it is in good condition before it departs.
The other options are incorrect because they are not the correct amount of time that the guard of a passenger train should sign on before the actual departure of the train.