The boom should not be operated if the truck is at more than a ___ degree incline unless extra precautions are taken.

The correct answer indicates that the boom should not be operated if the truck is at an incline greater than 5 degrees, unless additional safety measures are implemented. This is rooted in safety protocols and best practices for operating equipment on inclines since higher angles can significantly affect the stability and balance of the truck, as well as the boom itself. Operating at steeper inclines increases the risk of tipping or losing control of the equipment, potentially leading to accidents or operational failures. Therefore, adhering to the limit of 5 degrees ensures a higher safety margin, promoting safe operation and protecting both the operator and the equipment.