Label each of the following reactions as reduction, oxidation, or none of it.

• A. a. Reduction.
  b. Oxidation.
  c. Reduction.
• B. a. Oxidation.
  b. Step-1: Reduction, Step-2: Neither.
  c. Oxidation.
• C. a. Neither oxidation nor reduction.
  b. Oxidation.
  c. Reduction.
• D. a. Neither oxidation nor reduction.
  b. Step-1: Neither oxidation nor reduction, Step-2: Reduction.
  c. Oxidation.

Answer: (D)