Active immunity is obtained by

Options

A. Natural resistance
B. Antibiotics
C. Weakened germs infection
D. None of these

Answer

**Step-by-Step Solution:**

1. **Understanding Active Immunity**: Active immunity is a type of immunity that is developed by the body in response to an infection or vaccination. It involves the production of antibodies by the immune system.

2. **Identifying Sources of Active Immunity**: Active immunity can be obtained through:
- Natural exposure to pathogens (natural resistance).
- Vaccination with weakened or inactivated pathogens.

3. **Evaluating the Options**:
- **Natural Resistance**: This refers to the immunity developed by the body after exposure to pathogens. This is indeed a form of active immunity.
- **Antibiotics**: These are medications used to treat bacterial infections but do not provide active immunity. They are not produced by the immune system.
- **Weakened Germ Infection**: This refers to the use of weakened or inactivated pathogens in vaccines. While this does stimulate an immune response, it is not the same as natural immunity developed through direct exposure to the pathogen.
- **None of These**: This option does not apply as we have identified a valid source of active immunity.

4. **Conclusion**: The correct answer is **Natural Resistance**, as it is the only option that directly relates to the body’s own immune response leading to active immunity.

**Final Answer**: Active immunity is obtained by **Natural Resistance**.

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