Which type of surface is more favourable for evaporation?

Correct answer: Large and open water surface

Correct answer: C, a large and open water surface. Evaporation takes place at the surface of a liquid, where some molecules gain enough energy to escape into the air as vapour. A larger exposed surface provides more area from which molecules can escape at the same time. An open surface also allows the water vapour to disperse into the surrounding air, helping continued evaporation, especially when the air is not already saturated. A is wrong because a small covered surface has less exposed area and restricted contact with air. B is wrong because cooling reduces molecular energy and a closed surface limits exchange with the air. C is correct because it combines a large area with direct exposure to the atmosphere. D is wrong because a dry rocky surface is not itself a water surface; evaporation requires liquid water, although water held in cracks or on the rock may evaporate. Memory cue: spread water out and expose it to air—like wet clothes or a shallow tray—to increase evaporation.