Which one of the following is a transgenic product useful for the treatment of hemophilia?

Options

A. Factor VIII
B. Antithrombin II
C. `alpha`- 1-antitrypsin
D. Lysostaphin

Answer

### Step-by-Step Solution:

1. **Understanding Hemophilia**:
- Hemophilia is a genetic disorder that affects the blood's ability to clot, leading to excessive bleeding. It is primarily caused by deficiencies in specific clotting factors.

2. **Types of Hemophilia**:
- There are two main types of hemophilia:
- **Hemophilia A**: Caused by a deficiency in clotting factor VIII (factor 8).
- **Hemophilia B**: Caused by a deficiency in clotting factor IX (factor 9).

3. **Identifying the Transgenic Product**:
- The question asks for a transgenic product that is useful for treating hemophilia.
- Among the options provided:
- **Factor 8**: This is the clotting factor that is deficient in Hemophilia A.
- **Antithrombin**: A plasma cofactor, not directly related to hemophilia.
- **Alpha 1 Antitrypsin**: Protects body tissues from infection, not related to hemophilia treatment.
- **Lysostaphin**: An enzyme active against bacteria, not related to hemophilia.

4. **Conclusion**:
- Since Hemophilia A is treated with factor 8, the correct answer is **Factor 8**.