Answer:
The correct answer is "Oxidation at the anode and reduction at the cathode".
Step-by-step explanation:
A rechargeable battery is recharged by the movement of electrons from an external power source into the battery. In order to achieve this, two process take place inside the rechargeable battery: oxidation at the anode and reduction at the cathode. The electrons flow within the battery from the anode to the cathode, this happens by the oxidation of the anode (loss of electrons) and the reduction at the cathode (gain of electrons).