The correct options are
A Wait for the train to pass.
C Switch off the vehicles.
D Check the crossing signals and then pass.
There are a few safety measures that needs to be followed while we are at a level crossing. We should always wait at a level crossing for the train to pass. Also it is very dangerous to cross while the train is approaching. We should always switch off the vehicles while waiting at a level crossing inorder to save the fuel and reduce pollution. After the train passes, check the traffic signal and cross.