The correct answer is C. In a complete revolution of the armature, the current flow direction within the armature winding does reverse, whereas the current flow direction in the external load does not reverse. This is because in a basic DC generator, the commutator reverses the direction of the current flow within the armature winding with each half revolution, but the current direction in the external load remains constant. The commutator acts as a mechanical rectifier, converting the alternating current (AC) generated in the armature winding into direct current (DC) in the external circuit. The other options are incorrect because they do not accurately describe the current flow behavior in the armature winding and external load during a complete revolution of the generator's armature.