Final answer:
The best action for a train operator not receiving a proceed signal while operating from other than the front end is to stop and wait for clear signals. This ensures safety and prevents possible accidents on the tracks. Intuition about train operations is not a substitute for following proper signaling protocols.
Step-by-step explanation:
The question pertains to protocol for train operators when operating from a position other than the front end of a train and not receiving a proceed signal. In such a scenario, the best action for the train operator would be to Stop moving and become stationary until it is clear to continue. The reasons are tied to safety protocols and the need to ensure that the path ahead is clear and safe to proceed. Ignoring signal indications and proceeding without clearance could lead to dangerous situations, including collisions with other trains or obstructions on the track.
Experienced train operators and regular passengers may have an intuitive understanding of train schedules and operations, sensing delays or platform changes by the crowd's movements. However, when it comes to signal following, there is no room for intuition; strict adherence to signal indications is critical. In this context, action (a) from the provided options is the correct procedure to ensure the safety of the passengers and crew, and maintain operational integrity.