Explanation: In a DC motor, continuous rotation in one direction requires a mechanism to periodically reverse the current flowing through the armature coils. This ensures that the magnetic field generated by the armature always interacts with the stationary field coils to produce torque in the same rotational direction. The "connector" (referring to the commutator and brush assembly) fulfills this crucial role. As the armature rotates, the commutator segments make contact with the stationary brushes, periodically switching the electrical connection to the armature windings. This dynamic connection reverses the current flow in the appropriate coils at the correct time, maintaining continuous torque and preventing the motor from simply oscillating or stopping. A) Field coils create the stationary magnetic field but don't change armature connections. C) Brushes are stationary contacts that ride on the commutator but are not the primary component that "changes" the coils themselves. D) Auxiliary speed control manages motor speed, it's not part of the fundamental rotation mechanism.