Which of the following statements about the small intestine is true?

• A. It is composed of the duodenum, jejunum, and ileum.
• B. It produces bile for fat digestion.
• C. It is shorter than the large intestine.
• D. It is the primary site for nutrient absorption in the digestive system.

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by identifying the anatomical structure of the small intestine. The small intestine is divided into three main sections: the duodenum, jejunum, and ileum. These sections work together to perform digestion and absorption.
2. Step 2: Clarify the function of bile production. Bile is produced by the liver and stored in the gallbladder, not the small intestine. The small intestine uses bile to emulsify fats, but it does not produce bile itself.
3. Step 3: Compare the length of the small intestine to the large intestine. The small intestine is longer than the large intestine, typically measuring about 6 meters (20 feet) in length, while the large intestine is approximately 1.5 meters (5 feet).
4. Step 4: Highlight the primary function of the small intestine. The small intestine is the primary site for nutrient absorption in the digestive system. Its inner lining contains villi and microvilli, which increase the surface area for efficient absorption of nutrients into the bloodstream.
5. Step 5: Conclude by verifying the correct statement. Based on the anatomical and physiological functions of the small intestine, the correct answer is: 'It is the primary site for nutrient absorption in the digestive system.'