Final answer:
Option C). More melting occurs when coal dust is spread on snow on a sunny day because the coal dust's darker color leads to greater absorption of solar radiation, increasing the rate of snow melting.
Step-by-step explanation:
More melting happens when coal dust is applied to snow on a sunny day. This is due to the fact that coal dust absorbs more solar radiation than white snow because it is darker in color. Because snow and ice have a high albedo, they reflect the majority of the sun's energy and stay relatively cool. Snow melts more quickly, though, when it is covered in materials that have a low albedo, like coal dust, which absorbs more solar radiation. This idea is comparable to feeling warmer on a sunny day when wearing a black shirt because it absorbs more heat than a white shirt.
This is an illustration of a positive feedback mechanism, comparable to the process by which dark ice forms as a result of water melting in pools, absorbing more heat and hastening the melting of ice. The increased absorption of solar radiation in the case of coal dust on snow speeds up the melting process.