(i) It does not participate in the cell reaction.

(ii) It provides surface either for oxidation or for the reduction reaction.

(iii) It provides a surface for conduction of electrons.

(iv) It provides a surface for a redox reaction.

Correct Answer: (iv) It provides a surface for a redox reaction

Explanation:  An inert electrode is an electrode that acts as a source or sink of electrons. Precious metals, mercury and carbon are often used as inert electrodes. It provides an environment for oxidation or degradation but not with a redox response. Not involved in cell response.