The correct answer is B) Chocolate brown. When proper commutation is taking place in a DC motor, the commutator segments should have a chocolate brown color. This is the result of the natural oxidation process on the copper commutator bars, which occurs when the brushes make proper contact and the motor is operating correctly. The other answer choices are incorrect because: A) Burnished green indicates excessive wear on the commutator, C) Brick red suggests excessive sparking and poor commutation, and D) Shiny blue is not a normal color for a properly functioning DC motor commutator.