During switching operations, prior to shoving in any track, equipment must be ______ to ensure all cars and/or locomotives are coupled.

In the context of switching operations, prior to shoving cars onto a track, it is crucial for the equipment to be "stretched." This refers to a procedure where the slack in the couplings between cars is taken up to ensure they are properly coupled before any movement. This helps to prevent potential accidents or damage that may occur if the cars are not securely attached to one another.

The stretching process involves moving the cars a short distance to eliminate slack, ensuring that they are in a secure and firm connection. This practice enhances safety and operational efficiency during switching rail operations, as it allows for smoother transitions and minimizes the risk of derailments or unexpected separations while moving the cars.

The other choices pertain to different aspects of rail operations but do not specifically address the immediate requirement of ensuring that all cars are connected and ready for shoving. Checking might refer to a general overview, securing pertains more to the placement of equipment once stopped, and aligning relates to the positioning of tracks rather than the necessary coupling process before movement. Thus, the correct answer focuses specifically on the action needed to ensure secure coupling.