Where the blood is formed in human body?

Options

A. In heart
B. In spleen
C. In liver
D. In bone marrow

Explanation

**Step-by-Step Solution:**

1. **Understanding Blood Formation**: Blood is a vital fluid in the human body that is responsible for transporting oxygen, nutrients, and waste products. It is essential to know where blood is produced.

2. **Identifying the Options**: The question provides four options for where blood is formed:
- A) Heart
- B) Spleen
- C) Liver
- D) Bone Marrow

3. **Analyzing Each Option**:
- **Heart**: The heart is primarily a muscular organ that pumps blood throughout the body but does not produce blood.
- **Spleen**: The spleen plays a role in filtering blood and recycling iron but is not the primary site of blood formation.
- **Liver**: The liver has various functions, including detoxification and metabolism, but it is not the main site for blood production.
- **Bone Marrow**: Bone marrow is a soft, spongy tissue located inside the bones. It is the primary site for the production of blood cells, including red blood cells, white blood cells, and platelets.

4. **Conclusion**: Based on the analysis, the correct answer is **D) Bone Marrow**. This is where blood is formed in the human body.

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