The most abundant class of immunoglobulins (Igs) is the body is

Options

A. IgA
B. IgG
C. IgE
D. IgM.

Explanation

To solve the question about the most abundant class of immunoglobulins (Igs) in the body, we will analyze each option provided:

### Step-by-Step Solution:

1. **Identify the Immunoglobulins**: The options given are Immunoglobulin A (IgA), Immunoglobulin G (IgG), Immunoglobulin E (IgE), and Immunoglobulin M (IgM).

2. **Analyze Immunoglobulin A (IgA)**:
- IgA is primarily found in secretions such as saliva and breast milk.
- It constitutes approximately **10%** of the total immunoglobulins in the body.

3. **Analyze Immunoglobulin G (IgG)**:
- IgG is the most prevalent immunoglobulin and is known to cross the placenta, providing immunity to the fetus.
- It constitutes approximately **70-80%** of all immunoglobulins in the body.

4. **Analyze Immunoglobulin E (IgE)**:
- IgE is involved in allergic reactions and hypersensitivity.
- It is present in very small quantities, approximately **0.05%** of total immunoglobulins.

5. **Analyze Immunoglobulin M (IgM)**:
- IgM is the first antibody produced in response to an antigen.
- It constitutes about **5-10%** of the total immunoglobulins.

6. **Compare the Proportions**:
- IgA: 10%
- IgG: 70-80%
- IgE: 0.05%
- IgM: 5-10%

7. **Determine the Most Abundant Immunoglobulin**:
- From the analysis, it is clear that **IgG** is the most abundant immunoglobulin in the body, comprising 70-80% of the total immunoglobulins.

### Conclusion:
The most abundant class of immunoglobulins in the body is **Immunoglobulin G (IgG)**.

---