The process of vernalization can be induced by

Options

A. Cytokinin
B. Auxins
C. Phototropin
D. GA

Answer

### Step-by-Step Solution:

1. **Understanding Vernalization**:
- Vernalization is a biological process that promotes flowering in plants when they are exposed to a period of low temperatures. This process is crucial for certain plants to ensure that they flower at the right time of year, typically in spring.

2. **Identifying the Inducing Factors**:
- The question asks which substance can induce the process of vernalization. The options provided are cytokinin, auxins, phototropin, and gibberellic acid.

3. **Analyzing Each Option**:
- **Cytokinin**: This hormone primarily promotes cell division and growth but is not specifically known for inducing vernalization.
- **Auxins**: These are involved in various growth processes, including elongation and root formation, but they do not play a direct role in vernalization.
- **Phototropin**: This is a photoreceptor that helps plants respond to light, but it does not induce vernalization.
- **Gibberellic Acid**: This is a plant hormone that promotes growth and is known to play a significant role in the process of vernalization by facilitating flowering after a period of cold exposure.

4. **Conclusion**:
- Based on the analysis, gibberellic acid is the correct answer as it is the hormone that induces the process of vernalization in plants.

### Final Answer:
- The process of vernalization can be induced by **gibberellic acid**.