Find the odd one out from the options showing certain auxins.

Options

A. Indole acetic acid
B. 2,4-D
C. Indole butyric acid
D. Naphthalene acetic acid

Answer

To find the odd one out from the given options of auxins, we will analyze each option based on their nature (natural or synthetic) and their primary use.

### Step 1: Identify the Auxins
1. **Indole Acetic Acid (IAA)**: This is a natural auxin produced by plants. It plays a crucial role in various growth processes.
2. **2,4-Dichlorophenoxyacetic Acid (2,4-D)**: This is a synthetic auxin, primarily used as a herbicide to kill weeds.
3. **Indole Butyric Acid (IBA)**: This is also a natural auxin that is involved in root formation and plant growth.
4. **Naphthalene Acetic Acid (NAA)**: This is another natural auxin that promotes growth and is used in rooting and plant tissue culture.

### Step 2: Classify the Auxins
- **Natural Auxins**:
- Indole Acetic Acid (IAA)
- Indole Butyric Acid (IBA)
- Naphthalene Acetic Acid (NAA)

- **Synthetic Auxin**:
- 2,4-D

### Step 3: Identify the Odd One Out
From the classification, we can see that:
- IAA, IBA, and NAA are all natural auxins produced by plants.
- 2,4-D is a synthetic auxin, which is man-made and used primarily as a herbicide.

### Conclusion
The odd one out is **2,4-D** because it is the only synthetic auxin among the options provided.

---