Which item can be used for an improvised litter?

A blanket is a suitable choice for an improvised litter because it is flexible and can be easily manipulated to support a person who is injured or needing evacuation. It can conform to the shape of the individual being carried, providing comfort and support, and can help distribute weight evenly to make lifting easier. Blankets are also widely available and can be quickly deployed in emergency situations.

While a wooden board can provide a rigid support structure, it may not be as readily accessible or comfortable for the person being transported. Similarly, a plastic sheet is typically less supportive and may not provide the necessary structure to safely carry someone. A cushion, while soft, does not have the necessary durability or shape to effectively support a body during transport. Thus, the blanket stands out as the most practical and effective option for creating an improvised litter.