Correct Answer: copper at the cathode, and oxygen at the anode

Solution : The correct option is copper at the cathode and oxygen at the anode .

Copper is deposited at the cathode and is dissolved at the anode. Consequently, the concentration of copper ions in the solution remains constant. This can be used as a method of purification of copper as only pure copper is deposited at the cathode. Bubbles of gas (oxygen) are formed and evolved at the anode.

The equation will be as follows:

(cathode) Cu ⁺ + 2e ⁻ → Cu
(anode) Cu → Cu2 ⁺ + 2e ⁻