when the relative humidity is 100%, we say the air is (3 pts) a) saturated b) supercooled c) superheated d) very humid

The correct option is: a) saturated

Explanation:

Relative humidity is a primary measurement of humidity. At a given temperature, relative humidity describes the present state of absolute humidity relative to the maximum humidity.

It is generally expressed as percentage. Therefore, 100% relative humidity means that the air is entirely saturated.