The correct answer is D. Vitamin C.
Milk is a good source of calcium, protein, and carbohydrates. It is also a good source of phosphorus, potassium, riboflavin, and vitamin B12. However, milk is a poor source of vitamin C.
Vitamin C is a water-soluble vitamin that is essential for human health. It is involved in many important bodily functions, including the production of collagen, the absorption of iron, and the maintenance of a healthy immune system. Vitamin C is also a powerful antioxidant, which means that it can help to protect cells from damage caused by free radicals.
The recommended daily intake of vitamin C for adults is 90 milligrams. One cup of whole milk contains only 10 milligrams of vitamin C. Therefore, milk is not a good source of this important nutrient.
Other good sources of vitamin C include citrus fruits, tomatoes, broccoli, and strawberries.