A500 mb map shows a wavy wind pattern over the united states, where the wind direction is parallel to curved height contours. this can best be described as a .

a geostrophic
b strong
c weak
d gradient

D. gradient

Explanation:

In the map with wavy wind pattern over the United States , where the direction of the wind is parallel to the curved height contours .

This is best described as Gradient wind . As , when the wind blows parallel to the curved contour lines , then that wind is called gradient wind .

In geostropic as it is not blowing in a straight path parallel to evenly spaced lines .

Hence , the answer is D. gradient .