What type of powered rescue tool moves material using at least one movable arm?

Answer: B — Spreader

The type of powered rescue tool that moves material using at least one movable arm is the spreader. Spreaders are designed to create space by pushing or pulling objects apart, which is essential in rescue situations where access to a victim may be blocked by debris or vehicles. They operate using hydraulic power to extend and retract their arms, allowing for effective manipulation of various materials, such as metal or wood. The functionality of the spreader makes it particularly valuable in extrication scenarios, where creating space can be crucial for accessing trapped individuals safely. This distinguishes it from cutters, which primarily shear materials rather than move them. An extension ram is another tool used in rescue operations, but its main function is to push or pull objects rather than manipulate them with an arm-like movement. Thus, the spreader is specifically designed for the task of moving materials through its articulated arms, making it the correct answer.