What is required after receiving an A card to pass a stop block signal?

After receiving an A card, the requirement to pass a stop block signal is to have a Clearance Card Form K. This form is necessary for ensuring that the train is cleared to proceed past the stop block signal safely. The Clearance Card provides the necessary authorization and documentation, confirming that the area ahead is clear and that it is safe to continue.

This requirement is in place to maintain safety protocols and operational integrity along the tracks. It prevents potential collisions and ensures that all personnel are aware of the train's movements in potentially hazardous areas. The other choices do not fulfill the safety requirements necessary for passing a stop block signal after receiving an A card.