Erythropoiesis in human adults occurs in

Options

A. Bone marrow
B. Kidney
C. Liver
D. Spleen

Answer

**Step-by-Step Solution:**

1. **Understanding Erythropoiesis**: Erythropoiesis is the process of producing red blood cells (RBCs) in the body. This process is crucial for maintaining adequate oxygen levels in the blood.

2. **Identifying the Options**: The question asks where erythropoiesis occurs in human adults. The options provided are:
- A) Bone marrow
- B) Kidney
- C) Liver
- D) Spleen

3. **Analyzing Each Option**:
- **Option A: Bone Marrow**: In adults, erythropoiesis primarily occurs in the bone marrow. This is the correct answer.
- **Option B: Kidney**: While the kidneys produce erythropoietin, a hormone that stimulates red blood cell production, they do not directly carry out erythropoiesis. Therefore, this option is incorrect.
- **Option C: Liver**: The liver is involved in erythropoiesis during fetal development, but in adults, it does not play a significant role in this process. Thus, this option is incorrect.
- **Option D: Spleen**: Similar to the liver, the spleen can be involved in erythropoiesis during fetal development, but it is not a primary site for this process in adults. Hence, this option is also incorrect.

4. **Conclusion**: Based on the analysis, the correct answer is **A) Bone marrow**. This is where erythropoiesis occurs in human adults.