Select what is not true of intestinal villi among followings.

Options

A. They possess microvilli.
B. They increase the surface area.
C. They are supplied with capillaries and the lacteal vessels.
D. They only participate in digestion of fats.

Answer

### Step-by-Step Solution:

1. **Understanding Intestinal Villi**: Intestinal villi are small, finger-like projections found in the small intestine. They are formed by the mucosa layer of the alimentary canal.

2. **Function of Villi**: The primary function of the villi is to increase the surface area for absorption of nutrients. This is essential for effective digestion and absorption of food.

3. **Microvilli**: Each villus is covered with even smaller projections called microvilli, which further enhance the surface area and give the intestinal lining a brush border appearance.

4. **Vascular Supply**: Villi are rich in blood vessels (capillaries) and contain lymphatic vessels known as lacteals. These structures are crucial for the absorption of nutrients, including fats.

5. **Evaluating the Options**:
- The first option states that they possess microvilli, which is true.
- The second option states that they increase the surface area, which is also true.
- The third option states that they are supplied with capillaries and lacteals, which is correct.
- The fourth option claims that they only participate in the digestion of fats, which is not true. Villi are involved in the absorption of all types of nutrients, not just fats.

6. **Conclusion**: The statement that is not true about intestinal villi is that they "only participate in the digestion of fats." Therefore, the correct answer is the fourth option.