The absence of which clotting factor leads to haemophilia-A?

Options

A. Factor VII
B. Factor VII
C. Factor IX
D. Factor X

Explanation

**Step-by-Step Solution:**

1. **Understanding Hemophilia A**: Hemophilia A is a genetic disorder characterized by the inability of blood to clot properly. This condition leads to excessive bleeding even from minor injuries.

2. **Identifying Clotting Factors**: Blood clotting involves a series of proteins known as clotting factors. There are 13 major clotting factors, each playing a crucial role in the coagulation cascade.

3. **Finding the Relevant Factor**: The question specifically asks for the clotting factor whose absence leads to Hemophilia A.

4. **Analyzing the Options**:
- **Factor 7**: This factor is not associated with Hemophilia A.
- **Factor 8**: This is the correct answer as Hemophilia A is caused by a deficiency of clotting factor 8.
- **Factor 9**: This factor is associated with Hemophilia B, not A.
- **Factor 10**: This factor is involved in the clotting process but is not related to Hemophilia A.

5. **Conclusion**: Based on the analysis, the absence of clotting factor 8 leads to Hemophilia A.

**Final Answer**: The absence of clotting factor 8 leads to Hemophilia A.

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