The correct option is B Rotation of Turbine
A generator is a device which works on the principle of electromagnetic induction. Whenever the magnetic flux through a coil changes, an emf is induced across the ends of the coil, which leads to an induced current in the coil. Hence, when a coil is rotated in the presence of a magnetic field, a current is induced in the coil. Therefore the last step in the production of electricity is the rotation of turbine.