Which of the following statements is true regarding stabilization controls?

The statement that more than one control can be operated at a time is accurate in the context of stabilization controls used in aerial fire apparatus. This capability allows operators to enhance stability and safety when the apparatus is deployed, particularly in dynamic situations where immediate adjustments may be necessary. By being able to operate multiple controls simultaneously, the operator can optimize the apparatus's positioning and support, ensuring that it remains stable on various terrains and conditions.

The operational flexibility provided by this feature is crucial for effectively managing the apparatus during firefighting or rescue operations. It allows for greater responsiveness in adjusting stabilizer legs or outriggers as needed without the limitation of engaging one control at a time, which would hinder efficiency and response to changing conditions.

In contrast, other statements lack accuracy: the notion that stabilization controls must not be used simultaneously would limit the effectiveness of the apparatus, while stating that they should only be engaged manually disregards advancements in technology that may allow for automated systems. Moreover, the requirement for all controls to be tested individually could be impractical and inefficient, especially when real-time adjustments are necessary during operations.