During PDI on slide-outs, what alignments should be verified?

Verifying the alignments of slide-outs during the Pre-Delivery Inspection (PDI) is crucial for ensuring that they function correctly and do not cause issues during operation. The correct answer focuses on checking the front-to-rear and top-to-bottom alignments.

The front-to-rear alignment is important because it ensures that the slide-out is properly positioned relative to the main structure of the vehicle. If the slide-out is not aligned correctly in this direction, it could result in difficulties while extending or retracting the slide-out, potential binding, or even damage to the slide-out mechanism over time.

Additionally, the top-to-bottom alignment is significant because it ensures a proper seal when the slide-out is closed. If the top and bottom do not align accurately, gaps may form, which can lead to water intrusion, air leaks, and can compromise the thermal insulation of the unit.

Looking at the other choices, they do not provide the comprehensive alignments necessary for optimal slide-out operation. Thus, confirming both front-to-rear and top-to-bottom alignments is essential for a successful inspection and proper functionality of slide-outs.