Which among the following is a synthetic plant hormone?

Options

A. IAA
B. GA
C. 2, 4-D
D. ABA

Answer

To determine which among the given options is a synthetic plant hormone, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Understand the Options**: The options provided are:
- IAA (Indole-3-acetic acid)
- GA (Gibberellic acid)
- 2,4-D (2,4-Dichlorophenoxyacetic acid)
- ABA (Abscisic acid)

2. **Identify Synthetic vs. Natural**:
- **IAA (Indole-3-acetic acid)**: This is a naturally occurring plant hormone, specifically an auxin, which regulates various aspects of plant growth.
- **GA (Gibberellic acid)**: This is also a naturally occurring hormone found in plants and fungi, involved in promoting growth and development.
- **2,4-D (2,4-Dichlorophenoxyacetic acid)**: This is a synthetic auxin, widely used as a herbicide. It is not naturally occurring and is specifically designed for agricultural use.
- **ABA (Abscisic acid)**: This is another naturally occurring plant hormone that plays a role in plant stress responses and developmental processes.

3. **Conclusion**: Among the options, **2,4-D** is the only synthetic plant hormone. The other options (IAA, GA, and ABA) are all naturally occurring hormones.

### Final Answer:
The synthetic plant hormone among the options is **2,4-D**.

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