Passive immunity is provided through

Options

A. Exogenous supply of antigens
B. Exogenous supply of antibodies
C. Endogenous supply of antigens
D. Endogenous supply of antibodies

Answer

To answer the question "Passive immunity is provided through," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Passive Immunity**:
- Passive immunity refers to the immunity that is acquired through the transfer of antibodies from one individual to another. This type of immunity does not involve the host's immune system actively producing antibodies.

2. **Identifying Sources of Passive Immunity**:
- Passive immunity can be obtained naturally or artificially. Natural passive immunity occurs when antibodies are transferred from mother to child, while artificial passive immunity involves the administration of antibodies from an external source.

3. **Analyzing the Options**:
- The options provided are:
- Exogenous supply of antigen
- Exogenous supply of antibody
- Endogenous supply of antigen
- Endogenous supply of antibody
- We need to determine which of these options correctly describes how passive immunity is provided.

4. **Focusing on Antibodies**:
- Since passive immunity involves the transfer of antibodies, we should focus on the options that mention antibodies. The relevant option here is "exogenous supply of antibody."

5. **Conclusion**:
- Based on the understanding that passive immunity is provided through the transfer of antibodies from an external source, the correct answer is:
- **Exogenous supply of antibody.**