An ideal pesticide is one which

Options

A. Brings about complete control of a specific pest
B. Is non-toxic and biodegradable
C. Is non-persistent
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding the Concept of an Ideal Pesticide**:
An ideal pesticide is one that effectively controls specific pests without causing harm to humans, animals, or the environment.

2. **Complete Control of Specific Pest**:
The first characteristic of an ideal pesticide is that it should bring about complete control of a specific pest. This means that the pesticide should effectively eliminate the targeted pest species to prevent them from reproducing and causing further damage.

3. **Non-toxic**:
The second characteristic is that the pesticide should be non-toxic. This is crucial because pesticides are often used in agricultural settings where humans and animals may be exposed to them. A non-toxic pesticide ensures safety for consumers and the ecosystem.

4. **Biodegradable**:
The third characteristic is that the pesticide should be biodegradable. This means that the pesticide should break down naturally in the environment, reducing the risk of long-term contamination of soil and water sources.

5. **Non-persistent**:
The fourth characteristic is that the pesticide should be non-persistent. This means that it should not remain in the environment for extended periods. Non-persistent pesticides will degrade over time, minimizing their impact on the ecosystem.

6. **Conclusion**:
Since an ideal pesticide should possess all these characteristics—complete control of specific pests, non-toxicity, biodegradability, and non-persistence—the correct answer is that an ideal pesticide is one which has all of these properties.

### Final Answer:
The correct option is **D) All of this**.

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