Which document is used to permit a train to pass a stop block signal and enter an occupied block?

The correct answer is Clearance Card Form A, as this document is specifically designed for situations where a train needs authorization to pass a stop block signal and enter an occupied block. Clearance Card Form A provides the necessary permissions while ensuring that safety protocols are upheld. It signifies that the train has received clearance from a dispatcher or other authorized personnel to proceed despite the signal indication, allowing for safe operations in potentially risky situations.

In contrast, Clearance Card Form K typically relates to the exchange of track and time information, while Train Order T is generally used for the movement of trains according to specialized instructions rather than specifically for passing signals. Verbal Confirmation, while sometimes used in operations, does not provide the formal documentation required for passing a stop signal and does not ensure the same level of accountability in railroad operations as Clearance Card Form A.