Which of the following pair is not correctly matched?

Options

A. IgM- pentamer strongest antibody
B. IgG- universal antibody
C. IgA- secretory antibody
D. IgE- B- cell activator

Answer

To solve the question, we need to evaluate each option and determine if the pairs are correctly matched.

### Step-by-Step Solution:

1. **Option A: IgM is the pentamer strongest antibody**
- **Explanation**: IgM (Immunoglobulin M) is indeed a pentamer, meaning it consists of five monomeric units. It is the first antibody produced in response to an infection and is known for its strong ability to bind antigens. This statement is correctly matched.

2. **Option B: IgG universal antibody**
- **Explanation**: IgG (Immunoglobulin G) is the most abundant antibody in the blood and is known for its ability to cross the placenta, providing passive immunity to the fetus. However, it is not referred to as the "universal antibody." This term is misleading as it implies that IgG can be used universally for all types of infections or in all individuals, which is not accurate. Therefore, this statement is not correctly matched.

3. **Option C: IgA secretory antibody**
- **Explanation**: IgA (Immunoglobulin A) is indeed known as the secretory antibody. It is found in mucosal areas, such as the gut, respiratory tract, and urogenital tract, and is also present in secretions like saliva, tears, and breast milk. This statement is correctly matched.

4. **Option D: IgE B cell activator**
- **Explanation**: IgE (Immunoglobulin E) is primarily involved in allergic reactions and responses to parasitic infections. It is not primarily a B cell activator; rather, it binds to allergens and triggers histamine release from mast cells and basophils. This statement is also not correctly matched.

### Conclusion:
The pair that is not correctly matched is **Option B: IgG universal antibody**.