The correct answer is C. The diagram labeled C in the illustration EL-0057 depicts the proper method of aligning brushes on a commutator for a DC machine. The brushes should be aligned with the neutral axis, which is the position where the armature coils are not generating any voltage. This alignment ensures optimal performance and minimizes sparking at the commutator. The other answer choices are incorrect because they do not show the brushes aligned with the neutral axis, which is the proper configuration for a DC machine commutator.