Can a train use an A card to pass a stop block limit in 251 territory?

In 251 territory, a train is permitted to use an A card to pass a stop block limit under specific conditions. The A card is a form of authority that allows a train to operate under certain restrictions, specifically in situations where a cab signal is not available or where additional authority is needed for safe movement. Using the A card signals that the train has the authority to proceed, signifying that it can safely pass beyond the stop block limit within 251 territory.

Typically, the use of an A card includes protocols that ensure safe operations, meaning that train crews must follow established procedures to mitigate risk as they pass the stop block. Therefore, the correct answer reflects the fact that, with the valid use of the A card, a train can legally and safely proceed in these specific circumstances.

For context, options that suggest restrictions such as needing additional crew approval or limiting usage to emergencies do not align with the standard procedures established for using an A card in 251 territory. The rules provide clear authority under appropriate conditions, making the use of an A card both allowable and practical in ensuring smooth train operations.