In humans, placenta is derived from

Options

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

Answer

To solve the question "In humans, placenta is derived from," we will analyze the options provided and determine which one is correct.

### Step-by-Step Solution:

1. **Understanding the Placenta**: The placenta is a vital organ that develops during pregnancy, allowing for nutrient and gas exchange between the mother and the developing fetus. It is composed of both maternal and embryonic tissues.

2. **Analyzing the Options**:
- **Yolk Sac**: The yolk sac is an extra-embryonic structure that provides nutrition to the developing embryo in early stages. However, it does not form the placenta itself.
- **Amnion**: The amnion is a membrane that surrounds the amniotic cavity, which contains amniotic fluid. This fluid acts as a shock absorber for the fetus but is not involved in the formation of the placenta.
- **Allantois**: The allantois is involved in the formation of blood vessels and contributes to the development of the umbilical cord. However, it does not form the main structure of the placenta.
- **Chorion**: The chorion is the outermost membrane surrounding the embryo and is primarily responsible for the formation of the placenta. It contains trophoblasts that develop into chorionic villi, which facilitate nutrient exchange.

3. **Conclusion**: Based on the analysis, the correct answer is **Chorion**. It is the primary embryonic tissue that contributes to the formation of the placenta in humans.

### Final Answer:
The placenta in humans is derived from the **Chorion**.