- A Vitamin A, for vision and skin health
- B Vitamin B complex
- C Vitamin C, for collagen synthesis
- D Vitamin D, for calcium absorption
Correct answer: B. Vitamin B complex
Explanation: B vitamins (thiamine, riboflavin, niacin, etc.) act as coenzymes. For example, NAD+ is derived from niacin (Vitamin B3).
Concept context
Carbohydrates, proteins, lipids, nucleic acids, and enzyme kinetics. Essential foundation for understanding metabolism.