Which of the following represents a process in which a species is reduced?

Options
  • A. Hg(l) → Hg22 (aq)
  • B. Fe2 (aq) → Fe3 (aq)
  • C. NO3-(aq) → NO(g)
  • D. SO32-(aq) → SO42-(aq)
  • Correct Answer: Option D