The lapse rate measures what in the atmosphere?

The correct choice is that the lapse rate measures the variation of temperature with height in the atmosphere. This concept is fundamental to understanding atmospheric processes because it describes how temperature decreases as altitude increases in the troposphere. The lapse rate is important for aerial spraying operations since temperature gradients can affect the dispersion and effectiveness of pesticide applications.

Relative humidity is a measure of the amount of moisture in the air compared to the maximum it can hold at a given temperature, which is not what the lapse rate indicates. The time for pesticide spray to deposit concerns factors related to application techniques and environmental conditions, but it does not involve the principles of the lapse rate or thermal gradients in the atmosphere.