Which of the following structure is lacking from the placenta

Options

A. Arteries
B. Veins
C. Smooth muscles
D. Nerves

Explanation

**Step-by-Step Solution:**

1. **Understanding the Placenta**: The placenta is an organ that develops during pregnancy, serving as a connection between the mother and the developing embryo. It facilitates the exchange of nutrients, gases, and waste products.

2. **Identifying Structures in the Placenta**: The placenta contains several key structures:
- **Arteries**: These carry oxygenated blood from the mother to the fetus.
- **Veins**: These carry deoxygenated blood from the fetus back to the mother.
- **Smooth Muscles**: These are present to help regulate blood flow and support the structure of the placenta.

3. **Identifying Structures Not Present in the Placenta**: While arteries, veins, and smooth muscles are present in the placenta, nerves are not typically found in the placenta. The placenta functions primarily through the exchange of blood and does not require nerve innervation for its function.

4. **Conclusion**: Based on the analysis, the structure that is lacking from the placenta is **nerves**.

**Final Answer**: The structure lacking from the placenta is **nerves**.

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