A straight long conductor carries current along the positive x -axis. Identify the correct statement related to the four points A(a,a,0), B(a,0,a), C(a,−a,0) and D(a,0,−a) .
(a) The magnitude of magnetic field at all points is same
(b) Fields at A and B are mutually perpendicular
(c) Fields at A and C are antiparallel
(d) All of the above