Which of the following is an organic micronutrient that regulates certain processes in the body?

• A. Sodium chloride (NaCl)
• B. Vitamin C (ascorbic acid)
• C. Iron (Fe)
• D. Calcium ion (Ca^{2+})

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the term 'organic micronutrient.' Organic micronutrients are small molecules containing carbon that are essential for the body in small amounts and regulate various biological processes. Examples include vitamins.
2. Step 2: Analyze the options provided. Sodium chloride (NaCl), iron (Fe), and calcium ion (Ca^{2+}) are inorganic substances, as they do not contain carbon and are classified as minerals.
3. Step 3: Recognize that Vitamin C (ascorbic acid) is an organic compound because it contains carbon atoms and is a micronutrient essential for processes like collagen synthesis and antioxidant activity.
4. Step 4: Compare the properties of Vitamin C with the other options. Sodium chloride, iron, and calcium ions are involved in physiological functions but do not meet the criteria of being organic micronutrients.
5. Step 5: Conclude that the correct answer is Vitamin C (ascorbic acid), as it is the only organic micronutrient listed that regulates certain processes in the body.