The correct answer is B) stop uncontrolled bleeding. A tourniquet is a last-resort medical device used to stop life-threatening arterial bleeding by applying pressure to the limb to cut off blood flow. This can be crucial in situations where other methods of bleeding control, such as direct pressure or elevation, are not effective. Tourniquets should only be used for severe, uncontrolled bleeding that cannot be stopped by other means, as improper or prolonged use can lead to tissue damage. The other answer choices are incorrect because a tourniquet is not used to hold a victim in a stretcher (A), hold a large bandage in place (C), or restrain a delirious victim (D). These are not the primary functions of a tourniquet in emergency medical care.