The correct answer is A. T/369(3b).
T/369(3b) is a regulation that requires trains to be piloted into the station during reception when working on T/D912 in automatic block in system. This is to ensure that the train is safely brought to a stop in the station.
T/369(2) is a regulation that requires trains to be piloted into the station during departure when working on T/D912 in automatic block in system. This is to ensure that the train is safely brought to a start in the station.
T/369(1) is a regulation that requires trains to be piloted into the station during normal operation when working on T/D912 in automatic block in system. This is to ensure that the train is safely brought to a stop or start in the station.
T/409 is a regulation that requires trains to be piloted into the station during emergency operation when working on T/D912 in automatic block in system. This is to ensure that the train is safely brought to a stop or start in the station.
In conclusion, the correct answer is A. T/369(3b).