All bone marrow is red and involved in haematopoiesis in 

Options

A. Old people
B. Women
C. Newborn
D. Pregnant woman

Answer

To solve the question, "All bone marrow is red and involved in haematopoiesis in," we need to analyze the options provided: old people, women, newborns, and pregnant women.

### Step-by-Step Solution:

1. **Understanding Hematopoiesis**:
- Hematopoiesis is the process of blood cell formation, which primarily occurs in the bone marrow. There are two types of bone marrow: red and yellow. Red bone marrow is actively involved in hematopoiesis.

2. **Analyzing Each Option**:
- **Old People**:
- In older adults, the red bone marrow is often replaced by yellow bone marrow, leading to a reduced capacity for hematopoiesis. Therefore, this option is incorrect.

- **Women**:
- Women have both red and yellow bone marrow. While they can produce blood cells, not all of their bone marrow is red. Thus, this option is also incorrect.

- **Newborns**:
- Newborns have predominantly red bone marrow, which is highly active in producing red blood cells (RBCs). This makes this option likely correct.

- **Pregnant Women**:
- Pregnant women do experience increased blood volume and may have increased hematopoiesis, but they do not have all red bone marrow. They also possess yellow bone marrow. Therefore, this option is incorrect.

3. **Conclusion**:
- After analyzing all the options, we conclude that the correct answer is **newborns**, as they have all red bone marrow involved in hematopoiesis.

### Final Answer:
- **Newborns** are the correct answer since they have all bone marrow that is red and involved in hematopoiesis.

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