What authority is required to pass a stop signal in 251 single track territory?

To pass a stop signal in 251 single track territory, it is essential to have the appropriate authority to ensure both safety and compliance with operating protocols. The correct answer encompasses all the possible forms of authority required under different circumstances.

A Form L provides specific instructions and authority necessary for train movements, particularly in situations involving switch and signal control. This ensures that the train can proceed safely past a stop signal with a clear understanding of the conditions and limits of operation.

Verbal Rule 241 may also come into play, as it allows for verbal communication of authority to pass a stop signal under certain conditions, ensuring that all involved parties are adequately informed and that safety is maintained.

The K Card serves as a physical representation of the current operating conditions and clearances for movements in the territory, functioning as an additional layer of authority and safety check.

Since any one of these authorities may be applicable depending on the specific situation, the requirement to pass a stop signal in this territory is correctly represented by the choice that includes all of them. This comprehensive approach ensures maximum safety and adherence to operational standards.