Which is used as a weedicide ?

Options

A. Indole Acetic acid
B. Napthalene Acetic acid (NAA)
C. Indole Butyric acid (IBA)
D. 2, 4-D.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which chemical is used as a weedicide. A weedicide is a substance used to kill unwanted plants or weeds.

2. **Identifying the Options**: The options provided are:
- A) Indole Acetic Acid
- B) Naphthalene Acetic Acid
- C) Indole Butyric Acid
- D) 2,4-D (2,4-Dichlorophenoxyacetic acid)

3. **Analyzing Each Option**:
- **Indole Acetic Acid (IAA)**: This is a natural plant growth hormone, classified as an auxin. It promotes growth but is not used as a weedicide.
- **Naphthalene Acetic Acid (NAA)**: This is a synthetic plant growth regulator used to promote root formation and growth in plantlets. It is not a weedicide.
- **Indole Butyric Acid (IBA)**: Similar to IAA and NAA, this is also a synthetic auxin used for root development and plant growth. It is not a weedicide.
- **2,4-D (2,4-Dichlorophenoxyacetic Acid)**: This is a synthetic herbicide widely used to control broadleaf weeds. It is specifically designed to kill unwanted plants.

4. **Conclusion**: Based on the analysis, the correct answer is **D) 2,4-D**, as it is the only option that functions as a weedicide.

### Final Answer:
**D) 2,4-D (2,4-Dichlorophenoxyacetic acid) is used as a weedicide.**

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