A) at right angles and as far as practicable from each other is the correct answer. The best practice to minimize magnetic field interaction between electrical conductors in physical proximity is to orient them at right angles and as far apart as practically possible. This arrangement reduces the coupling between the magnetic fields generated by the conductors, minimizing any potential interference or induction between them. The other options are not correct because: B) placing the conductors parallel and close together would increase the magnetic field coupling; C) placing them at right angles but close together would still allow some magnetic field interaction; and D) aligning them parallel but far apart does not take advantage of the reduced coupling provided by the perpendicular orientation.