Final answer:
The pancreas is the organ that secretes a milky white fluid containing protein and digestive enzymes, known as pancreatic juice, into the duodenum for chemical digestion.
So, the correct answer is option 2.
Step-by-step explanation:
The pancreas plays a pivotal role in the chemical digestion process by producing pancreatic juice which contains a mixture of digestive enzymes and bicarbonate. These enzymes are crucial for breaking down proteins, carbohydrates, and fats into smaller molecules that can be absorbed by the intestine.
The pancreas delivers pancreatic juice into the duodenum, the first segment of the small intestine, where it neutralizes the acidic chyme coming from the stomach. The bicarbonate in the pancreatic juice serves to create a neutral environment that is optimal for the activity of these digestive enzymes.
That while the liver does produce bile, it is not milky white but rather a greenish fluid that emulsifies lipids, aiding their digestion and absorption. The gallbladder's function is to store and concentrate bile, but it does not produce the milky white fluid described. Salivary glands do secrete enzymes, but these are part of the saliva and not typically characterized as a milky white fluid either.
So, the correct answer is 2) Pancreas.