Which one is derivative of a carotenoid

Options

A. IAA
B. ABA
C. IBA
D. GA.

Answer

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a derivative of carotenoid among the given options: IAA, ABA, IBA, and GA.

2. **Analyze Each Option**:
- **Option A: IAA (Indole-3-acetic acid)**:
- IAA is a naturally occurring auxin derived from the amino acid tryptophan.
- Since it is derived from an amino acid and not from carotenoids, this option is incorrect.

- **Option B: ABA (Abscisic acid)**:
- ABA is known as the stress hormone and is formed in the chloroplasts of plants.
- It is synthesized from carotenoids, making it a derivative of carotenoid. This option is correct.

- **Option C: IBA (Indole-3-butyric acid)**:
- Similar to IAA, IBA is also an auxin derived from tryptophan.
- Therefore, it is not a derivative of carotenoids, making this option incorrect.

- **Option D: GA (Gibberellic acid)**:
- GA is a plant hormone that promotes growth and is derived from lipids.
- Since it is not derived from carotenoids, this option is also incorrect.

3. **Conclusion**: Based on the analysis, the correct answer is **Option B: ABA (Abscisic acid)**, as it is the only derivative of carotenoid among the given options.