Answer : 1. "Emulsion"
Explanation :

Answer: A) Emulsion Explanation: Milk is an emulsion of oil in water (o/w). Emulsion: A suspension of droplets of one liquid in another. Constituents of milk : The principal constituents of milk are water, fat, proteins, lactose (milk sugar) and minerals (salts). Milk also contains trace amounts of other substances such as pigments, enzymes, vitamins, phospholipids (substances with fatlike properties), and gases.