Answer: (2) During evaporation, the liquid particles absorb energy from the surroundings to regain the energy lost. As a result of this absorption of energy, the surroundings become cooler. Therefore, when exposed to air, the alcohol absorbed by the cotton plug starts evaporating and the temperature starts falling. Hence, the observation made by student B is correct. When evaporation is complete, there is no more absorption of energy from the surroundings. Consequently, the temperature starts increasing. Hence, the observation made by student C is also correct.