Which one of the following is not an organochlorine?

Options

A. Parathion
B. DDT
C. BHC
D. Aldrin

Answer

To determine which of the following compounds is not an organochlorine, we need to analyze each option based on their chemical structure and classification.

### Step-by-Step Solution:

1. **Understanding Organochlorines**:
- Organochlorines are compounds that contain carbon and chlorine, specifically chlorinated hydrocarbons. They must have at least one covalently bonded chlorine atom affecting their chemical behavior.

2. **Analyzing the Options**:
- **Option A: Parathion**
- Parathion is an organophosphate insecticide. Its structure does not contain any chlorine atoms. Therefore, it does not qualify as an organochlorine.

- **Option B: DDT (Dichlorodiphenyl trichloroethane)**
- DDT is known to contain chlorine atoms in its structure. It is classified as an organochlorine due to the presence of chlorine.

- **Option C: BHC (Benzene hexachloride)**
- BHC is a compound that contains multiple chlorine atoms. It is also classified as an organochlorine.

- **Option D: Aldrin**
- Aldrin is an organochlorine insecticide and contains chlorine in its structure, confirming its classification as an organochlorine.

3. **Conclusion**:
- After analyzing all the options, we find that **Parathion** is the only compound that does not contain chlorine and is therefore **not an organochlorine**.

### Final Answer:
**Parathion is not an organochlorine.**