Select the incorrect statement from the following .

Options

A. Agglutinin in plasma of blood group AB is Anti A and Anti B type .
B. Fibrinogens are activated by thrombins.
C. Albumin is the most abundant plasma protein.
D. Bombay blood group is a very rare blood group .

Answer

To solve the question, we need to analyze each statement regarding blood groups and their components. The goal is to identify the incorrect statement.

### Step-by-Step Solution:

1. **Understanding Agglutinins**:
- Agglutinins are antibodies present in the plasma that can cause blood cells to clump together (agglutination).
- Blood group AB has both antigen A and antigen B on the surface of its red blood cells.

**Hint**: Recall the role of agglutinins in blood typing and their relationship with blood group antigens.

2. **Analyzing the First Statement**:
- The statement claims that in blood group AB, the agglutinin in plasma is anti-A and anti-B.
- This is incorrect because blood group AB does not have anti-A or anti-B antibodies. Instead, it has both antigens (A and B) and no corresponding antibodies.

**Hint**: Remember that blood group AB has both antigens but does not produce antibodies against them.

3. **Analyzing the Second Statement**:
- The second statement claims that fibrinogen is activated by thrombin.
- This is correct; thrombin converts fibrinogen into fibrin, which is essential for blood clotting.

**Hint**: Consider the role of thrombin in the coagulation cascade.

4. **Analyzing the Third Statement**:
- The third statement claims that albumin is the most abundant plasma protein.
- This is true; albumin constitutes about 54% of the plasma proteins.

**Hint**: Recall the composition of plasma proteins and their functions.

5. **Analyzing the Fourth Statement**:
- The fourth statement mentions the Bombay blood group, which is indeed very rare and is represented as HH (recessive).
- This statement is correct as well.

**Hint**: Think about the rarity of the Bombay blood group and its genetic basis.

6. **Conclusion**:
- The first statement is the only incorrect statement among the options provided, as blood group AB does not contain anti-A and anti-B agglutinins.

### Final Answer:
The incorrect statement is: **"Agglutinin in plasma of blood group AB is anti-A and anti-B."**