Which of the following is NOT a recognized role of vitamin C (ascorbic acid)?

• A. Serving as a primary structural component of hemoglobin's heme porphyrin ring.
• B. Acting as a cofactor for enzymes that synthesize collagen and aiding iron absorption from plant foods.
• C. Functioning as a water-soluble antioxidant and supporting white blood cell production.
• D. Being readily excreted when consumed in large supplemental amounts because it is not stored extensively.

Answer: (A)