Right atrium receives blood from

Options

A. pulmonary aorta
B. pulmonary veins
C. inferior vena cava
D. superior and inferior vena cava.

Explanation

### Step-by-Step Solution:

1. **Understanding the Right Atrium**: The right atrium is one of the four chambers of the heart. It plays a crucial role in the circulatory system by receiving deoxygenated blood from the body.

2. **Identifying Blood Sources**: The right atrium receives blood from two major veins:
- **Superior Vena Cava (SVC)**: This vein carries deoxygenated blood from the upper parts of the body, such as the head, neck, and arms.
- **Inferior Vena Cava (IVC)**: This vein carries deoxygenated blood from the lower parts of the body, including the legs and abdomen.

3. **Function of the Right Atrium**: Once the right atrium receives blood from the SVC and IVC, it then pumps this deoxygenated blood into the right ventricle.

4. **Pathway of Blood**: From the right ventricle, the blood is then sent to the lungs via the pulmonary artery for oxygenation.

5. **Conclusion**: Therefore, the right atrium receives blood specifically from the superior vena cava and the inferior vena cava.

### Final Answer:
The right atrium receives blood from the **superior vena cava** and **inferior vena cava**.

---