If clouds arrive after frost formation what effect may occur on further cooling?

Correct answer: Clouds may reduce further radiational heat loss

The correct answer is A: clouds may reduce further radiational heat loss. At night, the ground loses heat by radiation and its temperature can fall enough for frost to form. Clouds act as a partial blanket because they absorb and re-radiate some outgoing terrestrial radiation back toward the surface. Therefore, after cloud cover arrives, the ground may cool more slowly, although the exact effect depends on cloud thickness, wind, humidity, and the existing temperature. B is wrong because clouds cannot turn the surface into lava; that is scientifically unrelated. C is wrong because clouds contain condensed water and do not simply remove all atmospheric vapour. D is wrong because frost and fog are different forms of condensation, and clouds do not guarantee that temperature will rise. Memory cue: clear skies favour rapid radiational cooling; cloudy skies usually reduce it.