The process of cooling due to evaporation is slow when the area of the water surface in contact with the atmosphere

Correct option is C

The process of cooling due to evaporation is slow when the area of the water surface in contact with the atmosphere decreases and the wind speed is low. So the correct answer is (c). 

Evaporation is the process of a liquid turning into a gas, and it requires energy to do so. This energy is taken from the surroundings, causing the liquid to cool down. Several factors influence the rate of evaporation, including: 

Surface area:

A larger surface area exposes more liquid molecules to the air, allowing for faster evaporation. 

Temperature:

Higher temperatures increase the kinetic energy of liquid molecules, making them more likely to escape as vapor. 

Humidity:

High humidity means the air is already saturated with water vapor, which slows down the evaporation process. 

Wind speed:

Wind removes water vapor from the surrounding air, creating space for more liquid molecules to evaporate. 

Therefore, if the surface area decreases (less liquid exposed to the air) and the wind speed is low (meaning water vapor doesn't get readily removed from the surrounding air), the rate of evaporation will be slow, resulting in slower cooling. 

Additional Information

(a) increases and the wind speed is high:

Both increasing surface area and high wind speed enhance evaporation. This leads to faster cooling. 

(b) increases and the wind speed is low:

While a larger surface area increases evaporation, low wind speed slows it down. The combined effect depends on the relative magnitudes of these factors. However, it is definitely not the condition for slow evaporation. 

(d) decreases and the wind speed is high:

A decrease in surface area slows evaporation. Even with high wind speed, the reduced surface area limits the amount of water vapor that can evaporate, resulting in slower cooling.