Technician A says that current is created in the stator windings of an alternator. Technician B says that the voltage regulator controls the current flow through the rotor. Who is right

Technician A and Technician B both are right.

Explanation:

In an AC alternator, there are two windings

1. Stator winding (stationary)

2. Rotor winding (rotating)

The current is induced in the stationary coils due to the magnetic field produced by the rotor. The DC suppy is provided to the rotor winding via slip rings and brushes and a voltage regulator precisely controls this supply to control the current flow through the rotor.

Therefore, both technicians are right.