In cyclic voltammetry, how can you distinguish a reversible redox couple from an irreversible one?

• A. Reversible shows slower electron transfer with larger ΔEp; irreversible shows fast transfer with small ΔEp.
• B. Reversible shows fast electron transfer with near-equilibrium behavior and small ΔEp; irreversible shows slower electron transfer with larger ΔEp and peak shifts.
• C. Reversibility depends only on electrode material, not on kinetics.
• D. In reversible systems, peak heights do not depend on scan rate; irreversible peaks do depend on scan rate.

Answer: (B)