The correct answer is A) changes direction clockwise, as from north to east, etc. In the Northern Hemisphere, a wind is said to veer when it changes direction clockwise. This is due to the Coriolis effect, which causes air masses in the Northern Hemisphere to be deflected to the right as they move. As a result, the wind direction shifts in a clockwise pattern. The other options are incorrect because B) changing direction counterclockwise is known as backing, C) a violent and erratic change in wind direction is not the definition of veering, and D) a constant wind direction does not represent the concept of veering.