The half-reaction at the cathode in an electrochemical cell is given below. What other half-reaction would most likely occur at the anode to produce a
spontaneous reaction?
Zn2+(aq) + 2e → Zn(s)

A. Zn(s) → Zn2+(aq) + 2e

B. Al(s) — A13+(aq) + 3e

C. K+(aq) + € → K(s)

D. H2(g) → 2H+(aq) + 2e