What material is commonly used for cushioning in orthotic devices?

C is commonly selected as the correct choice because EVA (ethylene-vinyl acetate) is widely recognized for its excellent cushioning properties. It is a lightweight, flexible, and durable material, making it ideal for use in orthotic devices where comfort and shock absorption are essential. EVA helps to reduce pressure on the feet and enhances overall comfort during movement, which is critical in orthotic applications.

Polyurethane also offers cushioning but tends to be denser and may not provide the same lightweight feel as EVA, which is crucial in foot health applications. Leather is more rigid and is often used for structural support rather than cushioning. Rubber, while it can offer some cushioning, is generally less effective than EVA in terms of shock absorption and flexibility, leading to its less common use in orthotic designs focused primarily on cushioning capabilities.