**Evaporation: The Conversion of a Liquid to a Gas at All Temperatures**

**Explanation:**

Evaporation is the process by which a substance changes from its liquid state to its gaseous state at temperatures below its boiling point. It is a type of vaporization that occurs at the surface of a liquid, where molecules with enough kinetic energy escape into the surrounding space as vapor or gas.

Evaporation occurs due to the random motion of molecules in a liquid. At any given temperature, some molecules in the liquid have higher kinetic energy than others. These high-energy molecules are more likely to overcome the intermolecular forces holding the liquid together and escape into the gas phase. As a result, the average kinetic energy and temperature of the remaining liquid decrease.

The process of evaporation can be affected by several factors:

1. Temperature: Increasing the temperature of a liquid increases the average kinetic energy of its molecules, leading to more molecules with enough energy to escape into the gas phase. Therefore, evaporation generally occurs more rapidly at higher temperatures.

2. Surface Area: Evaporation takes place at the surface of a liquid. Increasing the surface area of the liquid exposes more molecules to the surrounding space, increasing the rate of evaporation.

3. Air Flow: The presence of air flow can enhance evaporation by carrying away the vapor molecules from the liquid surface, maintaining a concentration gradient that favors continued evaporation.

4. Humidity: The humidity of the surrounding air affects the rate of evaporation. When the air is already saturated with water vapor (high humidity), it becomes more difficult for the liquid molecules to escape into the gas phase, slowing down the rate of evaporation.

**Conclusion:**

Evaporation is the process by which a liquid changes to a gas at all temperatures below its boiling point. It occurs due to the random motion of molecules and can be influenced by factors such as temperature, surface area, air flow, and humidity. Understanding evaporation is important in various fields, including weather and climate science, as well as industrial processes such as drying and distillation.

The answer is B. By the way if you know the answer then why are you asking the question ??