Question id 510 - Preflight Preparation - FAA PPL(A) - Private Pilot Airplane

The temperature of the surrounding air is at or below freezing when small drops of moisture fall on the collecting surface.
The temperature of the collecting surface is at or below freezing when small droplets of moisture fall on the surface.
The temperature of the collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is below freezing.

Training tests and timed exam simulations FAA PPL(A) - Private Pilot Airplane