Abscisic acid is useful in

Options

A. Cell division
B. Seed development
C. Germination of peanut seeds
D. Increasing length of stalks in grapes

Answer

### Step-by-Step Solution:

1. **Understanding Abscisic Acid (ABA)**:
- Abscisic acid is a plant hormone, often referred to as the "stress hormone." It plays a crucial role in plant responses to stress conditions.

2. **Functions of Abscisic Acid**:
- ABA is involved in several physiological processes in plants, including:
- **Stomatal Closure**: It promotes the closure of stomata to reduce water loss during stress conditions.
- **Seed Dormancy**: ABA induces dormancy in seeds, preventing them from germinating under unfavorable conditions.
- **Abscission**: It is involved in the shedding of leaves and fruits from the plant.
- **Senescence**: ABA plays a role in the aging process of plants.

3. **Comparison with Other Hormones**:
- While ABA is involved in inhibiting processes like germination and promoting dormancy, other hormones such as gibberellic acid (GA) promote seed germination, and cytokinins are involved in cell division.

4. **Analyzing the Options**:
- The question provides several options regarding the usefulness of abscisic acid:
- Cell division
- Seed development
- Germination of peanut seeds
- Increasing the length of the stalk in grapes
- Based on the functions of ABA, it is clear that it primarily affects seed development by promoting dormancy and inhibiting germination.

5. **Conclusion**:
- Therefore, the correct answer is that abscisic acid is useful in **seed development**, as it helps in maintaining seed dormancy and inhibiting germination under stress conditions.