Answer:
A) depends on the polarities of the armature and field currents.
Explanation:
In the DC series motor, or a universal motor, the field and armature winding are connected in series. This means that if the polarity of the input DC voltage is changed, the direction of the field & armature will also change, resulting in the change of direction of rotation of the motor. This means that the direction of rotation of a DC series motor, or a universal motor connected to a DC power source can be reversed by changing the polarity of the field current, or the armature current.