You can determine the wind direction by wetting your finger and holding it up in the air. Why?
A. The moisture on the finger evaporates faster in the direction of the wind.
B. The finger becomes colder on the side facing the wind due to evaporative cooling.
C. The wind causes a change in the electrical conductivity of the wet finger.
D. Wetting the finger creates a barrier against the wind, and the dry side indicates the wind direction.