Which plant hormone induces the phenomenon of photoropism in plants?

Options

A. Auxins
B. Ethylene
C. Cytokinin
D. Gibberellin

Explanation

To answer the question "Which plant hormone induces the phenomenon of phototropism in plants?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Phototropism**:
- Phototropism is the growth of a plant in response to light direction. Plants tend to grow towards light sources, which is crucial for maximizing photosynthesis.

2. **Identify Plant Hormones**:
- There are several plant hormones, including auxins, ethylene, cytokinins, and gibberellins. Each of these hormones has different roles in plant growth and development.

3. **Focus on Auxins**:
- Auxins are a class of plant hormones that play a significant role in promoting plant growth. They are particularly involved in the regulation of plant tropisms, including phototropism.

4. **Link Auxins to Phototropism**:
- Auxins promote cell elongation on the side of the plant that is away from the light. This differential growth causes the plant to bend towards the light source, resulting in phototropism.

5. **Conclusion**:
- Based on the understanding of plant hormones and their functions, the hormone that induces phototropism is **Auxins**.

### Final Answer:
The plant hormone that induces the phenomenon of phototropism in plants is **Auxins**.

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