Vaccines provide immunity by producing:

Options

A. antigens
B. antibodies
C. pathogens
D. None of these

Explanation

To answer the question "Vaccines provide immunity by producing:", we need to analyze the options provided: antigens, antibodies, pathogens, and none of these.

### Step-by-Step Solution:

1. **Understanding Vaccines**: Vaccines are substances that are introduced into the body to stimulate the immune system. They typically contain weakened or inactive parts of a particular organism (antigen) that triggers an immune response.

2. **Role of Antigens**: When a vaccine is administered, it introduces antigens into the body. Antigens are substances that the immune system recognizes as foreign and can trigger an immune response.

3. **Production of Antibodies**: In response to the antigens introduced by the vaccine, the body produces antibodies. Antibodies are specialized proteins that help to identify and neutralize pathogens such as bacteria and viruses.

4. **Pathogens**: While vaccines may contain parts of pathogens (like inactivated viruses or bacteria), they do not produce pathogens themselves. Instead, they use these components to stimulate the immune response.

5. **Conclusion**: The primary function of vaccines is to stimulate the production of antibodies in response to the antigens they contain. Therefore, the correct answer to the question is that vaccines provide immunity by producing **antibodies**.

### Final Answer:
Vaccines provide immunity by producing **antibodies**.

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