The correct answer is: A. PN
A PN is a Power of Necessity. It is a document that authorizes a train to proceed beyond a signal that is in the stop position. A PN is issued by the station master at the station in advance.
In push button token less territory, the train driver must obtain a PN from the station master before starting the train with for T/369(1) during signal failure at station in advance. This is because the train driver does not have a token to proceed beyond the signal. The PN authorizes the train driver to proceed beyond the signal and to stop at the next station.
The other options are incorrect because they do not authorize the train driver to proceed beyond a signal that is in the stop position.
A Non-PN is a document that authorizes a train to proceed beyond a signal that is in the proceed position. A Non-PN is issued by the signaller at the signal box.
Both is incorrect because the train driver must obtain a PN from the station master, not both a PN and a Non-PN.
None of these is incorrect because the train driver must obtain a PN from the station master, not none of these.