Allerthrin is

Options

A. Fertilizer
B. Herbicide
C. Growth hormone
D. Insecticide.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about "Allerthrin" and its classification among the given options: fertilizer, herbicide, growth hormone, or insecticide.

2. **Identifying the Nature of Allerthrin**: Allerthrin is identified as a synthetic pyrethroid. Pyrethroids are a class of chemicals that are commonly used as insecticides.

3. **Historical Context**: Allerthrin was developed in 1949, which indicates its long-standing use in pest control.

4. **Chemical Structure**: The chemical structure of Allerthrin is similar to natural pyrethroids, which are derived from chrysanthemum flowers. This similarity is significant as it relates to its effectiveness as an insecticide.

5. **Functionality**: Allerthrin is specifically used to target and kill flying and crawling insects, making it suitable for use in homes and workplaces.

6. **Conclusion**: Based on the above information, the correct classification of Allerthrin is as an insecticide.

**Final Answer**: Allerthrin is an insecticide.

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