The site of complete digestion of carbohydrates, proteins and fat is:

Correct option is B

Answer: (b) the small intestine

Explanation: The small intestine is the site of complete digestion of carbohydrates, proteins, and fats. Digestion begins in the mouth and stomach, but it is in the small intestine, with the help of digestive enzymes, that most of the digestion and absorption of nutrients occurs. The pancreas releases enzymes that aid in breaking down fats, carbohydrates, and proteins, and bile from the liver emulsifies fats.

Incorrect Options Explanations:
· The stomach: Incorrect. The stomach primarily digests proteins with the help of gastric juices, but it is not the site of complete digestion of carbohydrates, proteins, and fats.
· The large intestine: Incorrect. The large intestine absorbs water and electrolytes and is involved in the formation of stool, but it does not complete digestion of food.
· The rectum: Incorrect. The rectum is part of the large intestine and is involved in storing stool, not in digestion.

Information Booster:
· The small intestine consists of three parts: duodenum, jejunum, and ileum. The duodenum is where the majority of digestion occurs, while the jejunum and ileum are mainly involved in the absorption of nutrients.
· The process of digestion in the small intestine is facilitated by enzymes like amylase (carbohydrates), lipase (fats), and protease (proteins).
· Bile from the liver plays a key role in fat digestion by breaking down fats into smaller droplets.
· The pancreas produces pancreatic juice, which contains a variety of digestive enzymes.