Answer:
A current through a horizontal power line flows in the east to west direction. The direction of the magnetic field at a point directly below it is from South to north.
Explanation:
The current is in the east-west direction. Applying the right-hand thumb rule, we get that the direction of the magnetic field at a point below the wire is from north to south. The direction of the magnetic field at a point directly above the wire is from south to north.
