Where the blood is purified ?

Options

A. In Kidney
B. In lungs
C. In liver
D. In heart

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks where blood is purified in the body.

2. **Consider the Options**: The options provided are the kidney, lung, liver, and heart. We need to analyze each organ's function related to blood purification.

3. **Analyze the Kidney**: The kidneys are primarily responsible for filtering blood. They remove waste products, such as urea, and excess substances, thus purifying the blood. This process occurs in the nephrons, which are the functional units of the kidneys.

4. **Examine the Lung**: The lungs are involved in gas exchange, specifically the exchange of carbon dioxide and oxygen. They do not purify blood in the same way the kidneys do.

5. **Evaluate the Liver**: The liver plays a crucial role in detoxification, processing drugs and toxins, but it does not purify blood in the sense of removing waste products like the kidneys.

6. **Look at the Heart**: The heart's primary function is to pump blood throughout the body. It is not involved in the purification of blood.

7. **Conclusion**: Based on the analysis, the organ responsible for blood purification is the kidney.

8. **Final Answer**: The blood is purified in the kidneys.

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