Which one of the following is least persistent insecticide?

Options

A. Aldrin
B. Dieldrin
C. BHC
D. Carbamates

Answer

To determine which insecticide is the least persistent among the given options (Aldrin, D-Aldrin, BHC, and Carbamates), we can analyze each option based on their persistence in the environment.

### Step-by-Step Solution:

1. **Understanding Persistence**:
- Persistence refers to how long a substance remains in the environment without breaking down. Insecticides that are least persistent break down quickly.

2. **Analyzing Aldrin**:
- Aldrin is known to be highly toxic and does not break down quickly in the environment. Therefore, it is not the least persistent insecticide.

3. **Analyzing D-Aldrin**:
- Similar to Aldrin, D-Aldrin is also highly toxic and has a long half-life in the environment. Thus, it is not the least persistent insecticide either.

4. **Analyzing BHC (Benzene Hexachloride)**:
- BHC is harmful and has a moderate persistence in the environment. It is used to kill microorganisms but is not the least persistent among the options.

5. **Analyzing Carbamates**:
- Carbamates, which include compounds like carbamile and methomyl, are known for their rapid detoxification and elimination from animal tissues. They break down quickly in the environment, making them the least persistent insecticides among the options provided.

6. **Conclusion**:
- Based on the analysis, the least persistent insecticide is **Carbamates**.

### Final Answer:
The least persistent insecticide is **Carbamates**.