The correct option is (c).
Explanation
Milk is a nutrient-dense biological fluid secreted by the mammary glands of mammals. It acts as a colloidal suspension (emulsion) containing water, lipids, carbohydrates, proteins, vitamins, and minerals essential for growth and sustenance.
Statement-wise Analysis:
- Statement 1 is Correct: Milk is a significant source of high-quality proteins. The two main types of proteins found in milk are casein (constituting about 80% of the total protein) and whey proteins (constituting about 20%). These proteins provide essential amino acids.
- Statement 2 is Incorrect: Milk is not devoid of fat. Natural milk contains fat in the form of globules emulsified in the aqueous phase. The fat content varies by species (e.g., buffalo milk generally has higher fat content than cow milk). While "skimmed milk" is processed to remove fat, natural milk inherently contains lipids.
- Statement 3 is Correct: Milk contains fat-soluble vitamins, including Vitamin D, though natural levels can vary based on the animal's diet and sunlight exposure. It is also a standard practice in many regions to fortify commercial milk with Vitamin D to enhance calcium absorption and bone health.
Key Takeaway:
Milk contains proteins (casein, whey), fats, carbohydrates (lactose), and essential micronutrients like Calcium and Vitamin D. However, it is notably poor in Iron and Vitamin C.