A stick immersed in water appears bent due to the refraction of light (Option C). Refraction occurs when light changes speed and direction as it passes from one medium to another, such as from water to air. This change in speed causes the light rays to bend at the interface between the two media. For an observer, this bending results in a shift in the apparent position of the stick. The part of the stick submerged in water appears to be at a different angle compared to the part above the surface, creating the illusion that the stick is bent. This optical phenomenon is influenced by the refractive indices of water and air and the angle at which the light enters and exits the water. As a result, the stick appears displaced and bent at the water’s surface, demonstrating the effects of refraction.