Concept:Milk is rich in many nutrients, but it is a poor source of vitamin C (ascorbic acid).Explanation:Milk contains water (87.5%), fat (3.9%), protein (3.4%), lactose (a carbohydrate), and minerals like calcium and phosphorus. It also has vitamins A, D, B12, and potassium. However, vitamin C is present in very small amounts or is easily destroyed during processing. Good sources of vitamin C are citrus fruits like lemons and oranges. Milk is therefore not considered a significant source of vitamin C. Its deficiency causes scurvy, which leads to gum swelling and bleeding.Answer:Vitamin C (Option C)