Two straight horizontal parallel wires are carrying the same current in the same direction, d is the distance between the wires. You are provided with a small freely suspended magnetic needle. At which of the following positions will the orientation of the needle be independent of the magnitude of the current in the wires [NCERT 1983]

• A.   At a distance \[d/2\] from any of the wires
• B.   At a distance \[d/2\] from any of the wires in the horizontal plane
• C.   Anywhere on the circumference of a vertical circle of radius d and centre halfway between the wires
• D.   At points halfway between the wires in the horizontal plane