Haemophilia is a genetic disorder in which

Options

A. blood clots in blood vessels
B. There is delayed coagulation of blood
C. Blood fails to coagulate
D. Blood cell count falls

Explanation

**Step-by-Step Solution:**

1. **Understanding Haemophilia:**
- Haemophilia is a genetic disorder that affects the blood's ability to clot. This means that individuals with haemophilia experience prolonged bleeding after injuries or surgeries.

2. **Identifying the Cause:**
- The disorder is caused by a deficiency in specific clotting factors, which are proteins necessary for blood coagulation. The two main types of haemophilia are:
- **Haemophilia A:** Caused by a deficiency of clotting factor VIII (8).
- **Haemophilia B:** Caused by a deficiency of clotting factor IX (9).

3. **Analyzing the Options:**
- The question provides several options about the nature of haemophilia:
- A) Blood clots in blood vessels
- B) There is delayed coagulation of blood
- C) Blood fails to coagulate
- D) Blood cell count fails

4. **Evaluating the Correct Option:**
- Option A (Blood clots in blood vessels) is incorrect because haemophilia leads to improper clotting, not excessive clotting.
- Option C (Blood fails to coagulate) is misleading; while clotting is impaired, it does not mean that coagulation is entirely absent.
- Option D (Blood cell count fails) is unrelated to haemophilia, as it specifically pertains to clotting factors, not blood cell counts.
- Therefore, the correct answer is **B) There is delayed coagulation of blood.**

5. **Conclusion:**
- Haemophilia is characterized by delayed coagulation due to insufficient levels of clotting factors, leading to increased bleeding risk.