Temperature decreases as elevation increases.

Explanation:
When we talk about elevation, we are referring to the height or distance above sea level. As elevation increases, there are several factors that change, including temperature. Here's an explanation of why temperature decreases as elevation increases:

1. Relationship between temperature and altitude:
As we move higher above sea level, the atmospheric pressure decreases. The pressure at higher altitudes is lower because there is less air above to exert pressure. The decrease in pressure leads to a decrease in temperature. This relationship between temperature and altitude is known as the lapse rate.

2. Adiabatic cooling:
As air rises to higher altitudes, it expands due to the lower pressure. According to the gas laws, when air expands, the temperature decreases. This process is known as adiabatic cooling. As a result, the air becomes cooler as it rises to higher elevations.

3. Absorption and reflection of sunlight:
At higher elevations, the atmosphere is thinner, and there is less air to absorb and retain heat. The thinner atmosphere allows more sunlight to pass through without being absorbed. Additionally, the angle at which sunlight reaches the Earth's surface changes with elevation. At higher altitudes, the angle is usually steeper, resulting in less direct sunlight and lower temperatures.

4. Orographic effect:
Elevation changes can also affect temperature through the orographic effect. When air is forced to rise over mountains or elevated terrain, it cools as it gains altitude. This cooling effect can lead to lower temperatures in mountainous regions compared to lower-lying areas.

Conclusion:
In summary, as elevation increases, the temperature decreases due to the relationship between temperature and altitude, adiabatic cooling, reduced absorption and reflection of sunlight, and the orographic effect. Therefore, option B is the correct answer.