The correct answer is: Water.
Water is the second largest component in milk, accounting for about 87% of its weight. It is essential for the transport of nutrients and other substances in the body, and it also helps to regulate body temperature.
Fat is the largest component in milk, accounting for about 3.5% of its weight. It is a source of energy and essential fatty acids, and it also helps to absorb fat-soluble vitamins.
Minerals are present in milk in small amounts, but they are essential for good health. Calcium is the most important mineral in milk, and it is essential for strong bones and teeth. Other minerals found in milk include phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, copper, iodine, and selenium.
Sugar is present in milk in small amounts, and it is a source of energy. The type of sugar found in milk is lactose, which is a disaccharide made up of glucose and galactose. Lactose is broken down into glucose and galactose in the small intestine, and these sugars are then absorbed into the bloodstream.
In conclusion, the second largest component in milk is water. It is essential for the transport of nutrients and other substances in the body, and it also helps to regulate body temperature.