Within yard limits, what is required to make a movement not authorized by timetable schedule or train order?

The correct answer highlights the importance of maintaining safety and communication protocols within yard limits. When a movement is not authorized by a timetable schedule or a train order, it is necessary to ensure that the move can be safely executed. Proper signal indication, along with the permission of the block operator, is essential to guarantee that the route is clear and that all safety measures are in place before proceeding.

The signal indication plays a critical role in informing the crew of the current status of the track and ensuring that any potential hazards or conflicting movements are being taken into account. Obtaining permission from the block operator adds an additional layer of authority and oversight, ensuring that the movement is indeed safe and authorized within the current operational parameters of the yard.

In contrast, other possible options do not provide the same level of assurance or adherence to established protocols necessary for ensuring safety in yard operations. This makes the combination of proper signal indication and the block operator's permission the most reliable choice for such movements.