In human, placental villi are derived from

Options

A. Chorion
B. Allantois
C. Yolk sac
D. Amnion

Answer

To solve the question "In human, placental villi are derived from," we need to analyze the options provided and understand the development of the placenta in humans.

### Step-by-Step Solution:

1. **Understanding Placental Villi**:
- Placental villi are small, finger-like projections that form part of the placenta. They play a crucial role in nutrient and gas exchange between the mother and the developing fetus.

2. **Identifying the Source of Placental Villi**:
- The placental villi are specifically derived from a layer of the placenta known as the chorion. The chorion is one of the membranes that surround the embryo and is involved in the formation of the placenta.

3. **Function of the Chorion**:
- The chorion not only gives rise to the villi but also serves as a protective barrier for the developing embryo. The chorionic villi facilitate the transfer of nutrients and oxygen from the maternal blood to the fetal blood.

4. **Reviewing Other Options**:
- **Allantois**: This structure is an extension of the posterior wall of the yolk sac and is primarily involved in waste storage, not in forming villi.
- **Yolk Sac**: This membranous sac provides early nourishment to the embryo but does not form the villi.
- **Amnion**: This membrane surrounds the embryo and contains amniotic fluid, providing cushioning, but it is not involved in forming the villi.

5. **Conclusion**:
- Based on the analysis, the correct answer to the question is that placental villi are derived from the chorion.

### Final Answer:
The placental villi in humans are derived from the **chorion**.

---