Which of the following could be used as a splint from your military equipment?

Using a bayonet as a splint demonstrates an understanding of the need for immediate stabilization of an injury in a combat or field situation. A bayonet, being rigid and typically made from metal, can effectively immobilize a fractured limb, preventing further injury to the affected area while awaiting more comprehensive medical assistance.

It's important to note that other items listed, such as a uniform, while potentially useful in a makeshift way, do not provide the same level of support or structure needed for a splint. The combat helmet, although protective, is designed for head defense and does not lend itself to the same splinting capabilities as a bayonet. A first aid kit is essential for providing initial care but does not typically contain a rigid splinting material that meets the immediate need for stabilization found in a field setting.