The hormone widely used as antitranspirant

Options

A. Cytokinin
B. ABA
C. auxin
D. Gibberellin

Answer

### Step-by-Step Text Solution:

1. **Understanding the Question**: The question asks for the hormone that is widely used as an antitranspirant. Antitranspirants are substances that reduce transpiration in plants, which is the loss of water vapor from the aerial parts of the plant.

2. **Identifying the Hormones**: The options provided are:
- Cytokinin
- Abscisic Acid (ABA)
- Auxin
- Gibberellin

3. **Analyzing Each Option**:
- **Cytokinin**: This hormone is involved in cell division and helps in delaying leaf senescence. It does not primarily function as an antitranspirant.
- **Abscisic Acid (ABA)**: This hormone is known as the stress hormone. It plays a crucial role in reducing transpiration and increasing water resistance in plants, especially under water stress conditions.
- **Auxin**: This hormone is involved in growth processes such as phototropism (growth towards light) and apical dominance. It does not function as an antitranspirant.
- **Gibberellin**: This hormone is responsible for promoting growth processes such as seed germination and stem elongation, but it does not act as an antitranspirant.

4. **Conclusion**: Based on the analysis, the hormone that is widely used as an antitranspirant is **Abscisic Acid (ABA)**. It reduces transpiration and helps plants cope with water stress.

5. **Final Answer**: The correct option is **Abscisic Acid (ABA)**.