Before setting, the Sun appears elliptical because

Before setting, the Sun appears elliptical due to atmospheric refraction. The correct answer is [C] There is an effect of refraction of light. As the Sun nears the horizon, its light travels through a thicker layer of Earth’s atmosphere. This atmospheric layer bends the Sun’s light rays slightly, causing them to follow a curved path. The refraction effect is stronger near the horizon because the light passes through more of the atmosphere’s denser layers. This bending of light results in the Sun appearing distorted and stretched out horizontally, giving it an elliptical or flattened shape. Option A is incorrect because the Sun does not change its actual shape. Option B, light scattering, does not cause the Sun to appear elliptical but may affect its color or brightness. Option D, diffraction of light, involves bending of light around obstacles and is not responsible for the elliptical appearance of the Sun at sunset. Therefore, the correct explanation is the refraction of light (option C), which occurs due to the bending of light rays as they pass through the Earth’s atmosphere near the horizon.