Hormone responsible for ageing is

Options

A. GA
B. I A A
C. ABA
D. cytokinin

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the hormone responsible for aging in plants. This involves identifying the phytohormones and their roles in plant growth and development.

2. **Identifying Phytohormones**: Phytohormones are essential for various functions in plants, including growth, development, and aging. Some of the key phytohormones include:
- **Zebulin (Zebulic Acid)**: Primarily involved in cell division and elongation.
- **Auxin (IAA)**: Known for promoting growth, rooting, and cell division.
- **Cytokinins**: Involved in cell division and promoting apical dominance.
- **Abscisic Acid (ABA)**: Plays a crucial role in plant aging and senescence.

3. **Analyzing Each Hormone**:
- **Zebulin**: Not responsible for aging; focuses on growth.
- **Auxin**: Promotes growth but does not directly relate to aging.
- **Cytokinins**: Involved in growth and development but not specifically in aging.
- **Abscisic Acid (ABA)**: This hormone is specifically linked to the aging process and senescence in plants.

4. **Conclusion**: Based on the analysis, the hormone responsible for aging in plants is **Abscisic Acid (ABA)**.

### Final Answer:
The hormone responsible for aging is **Abscisic Acid (ABA)**.

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