Two Very Long Parallel Wires Are a Distance D Apart

Multiple Choice

Two very long parallel wires are a distance d apart and carry equal currents in opposite directions. The locations where the net magnetic field due to these currents is equal to zero are

A) midway between the wires.
B) a distance d/2 to the left of the left wire and also a distance d/2 to the right of the right wire.
C) a distance d to the left of the left wire and also a distance d to the right of the right wire.
D) a distance d/ to the left of the left wire and also a distance d/ to the right of the right wire.
E) The net field is not zero anywhere.