Active immunity means

Options

A. resistance developed before disease
B. resistance developed after disease
C. increased heart beat
D. increased flow of blood

Answer

### Step-by-Step Solution:

1. **Understanding Active Immunity**:
- Active immunity refers to the immunity that develops as a result of exposure to an antigen. This can occur naturally when a person is infected by a pathogen or artificially through vaccination.

2. **Evaluating the Options**:
- **Option 1**: "Resistance developed before disease."
- This is incorrect because active immunity develops after exposure to the antigen.
- **Option 2**: "Resistance developed after disease."
- This is correct. Active immunity is characterized by the body’s immune response following exposure to an antigen.
- **Option 3**: "Increase heart beat."
- This is unrelated to the concept of active immunity and is incorrect.
- **Option 4**: "Increase flow of blood."
- This is also unrelated to active immunity and is incorrect.

3. **Conclusion**:
- The correct answer is **Option 2**: "Resistance developed after disease."