Answer:
a. counterclockwise perpendicular to isobars
Explanation:
Due to the Coriolis force that shifts the air in such a way that it follows the pressure contours thereby making the air or wind blow in a counter-clockwise direction in the Northern Hemisphere around low pressure and move out around high pressure in a clockwise direction.
Hence, it can be concluded that The wind around a surface with low pressure in the Northern Hemisphere blows "counterclockwise perpendicular to isobars."
