Question

which term describes the relative amount of water vapor in the air?
saturation
aridity
humidity
dew point

Explanation:

Humidity is the term for the relative amount of water - vapor in the air. Saturation refers to the point where air can hold no more water - vapor. Aridity is related to dryness of a region. Dew - point is the temperature at which air becomes saturated with water - vapor.

Answer:

C. humidity