Antibodies which stick to the surface of microbes are

Options

A. Antioxins
B. Agglutinins
C. Osponins
D. Precipiins

Answer

### Step-by-Step Solution:

1. **Understanding Antibodies**: Antibodies are proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses.

2. **Function of Antibodies**: One of the key functions of antibodies is to bind to the surface of microbes. This binding helps in marking these microbes for destruction.

3. **Opsonins**: The specific type of antibodies that stick to the surface of microbes are called **opsonins**. Opsonins enhance the process of phagocytosis, which is the engulfing and digesting of pathogens by immune cells.

4. **Mechanism of Action**: When opsonins bind to the surface of microbes, they mark these microbes as targets for immune cells. This process significantly enhances the ability of immune cells, such as macrophages and neutrophils, to recognize and eliminate these pathogens.

5. **Role in Immune Response**: Opsonins not only mark pathogens for destruction but also activate the complement system, which is a group of proteins that aids in the immune response and can lead to the lysis (breaking down) of pathogens.

6. **Conclusion**: Therefore, the correct answer to the question is that the antibodies which stick to the surface of microbes are called **opsonins**.