Which of the following is NOT a basic function of litters in the high-angle environment?

In a high-angle rescue environment, litters are designed primarily to safely transport individuals who are sick or injured. The basic functions of litters include carrying the subject and stabilizing them during transport to prevent further injury. Additionally, litters are equipped to facilitate the safe attachment of the subject to the rescue system, ensuring that the individual remains secure while being moved.

The choice related to providing support for the rescuer while being lowered is not a fundamental function of litters. Litters are primarily intended for the subject being transported, not for aiding the rescuer's stability or support during the lowering process. The design and purpose of litters focus on the well-being and safety of the injured person rather than acting as a support mechanism for the rescuer. Thus, the correct answer highlights a key aspect of a litter’s intended use in rescue operations, distinguishing it from other equipment that might be utilized to support a rescuer's safety during such maneuvers.