Biological control means

Options

A. The control of harmful insects
B. The control of weeds
C. The control of pests and weeds through some specific organisms
D. None of the above

Answer

### Step-by-Step Solution:

1. **Understanding Biological Control**: Biological control refers to the method of controlling harmful organisms such as pests, weeds, and diseases using other living organisms. This method is an eco-friendly alternative to chemical pesticides.

2. **Identifying the Components**: The organisms used in biological control can include various types of living organisms, such as insects, microbes, or other plants that can help suppress the growth of harmful species.

3. **Examples of Biological Control**:
- **Use of Insects**: Certain insects, like flea beetles, can be introduced to control weed populations.
- **Microbial Agents**: Bacteria such as Bacillus thuringiensis (Bt) can be used to target specific pests without harming beneficial insects.
- **Predatory Organisms**: Decapitating flies can be used to control populations of fire ants.

4. **Conclusion**: Based on the definition and examples provided, biological control specifically refers to the control of pests and weeds through the use of specific organisms.

5. **Final Answer**: Therefore, the correct answer to the question "Biological control means" is: **the control of pests and weeds through some specific organisms**.