Pick up correct statements
(A) Cytokinins delay senescence
(B) Auxin regulate apical dominance
(C) Ethylene enhances seed germination
(D) Gibberellins cause falling of immature leaves.

Options

A. a, c
B. a,d
C. a, b
D. b, c

Answer

To determine the correct statements from the provided options regarding plant hormones, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A: Cytokinins delay senescence.**
- Cytokinins are plant hormones that promote cell division and play a significant role in delaying senescence (aging) in plants. Therefore, this statement is **correct**.

2. **Statement B: Auxin regulates apical dominance.**
- Auxins are responsible for the regulation of apical dominance, which is the phenomenon where the main central stem grows more vigorously than the side stems. This is due to the higher concentration of auxins in the apical bud. Thus, this statement is also **correct**.

3. **Statement C: Ethylene enhances seed germination.**
- Ethylene is primarily involved in processes such as fruit ripening and abscission. It does not enhance seed germination; rather, gibberellins are the hormones that promote seed germination. Therefore, this statement is **incorrect**.

4. **Statement D: Gibberellins cause falling of immature leaves.**
- Gibberellins are known for promoting growth, particularly stem elongation, and do not cause the falling of immature leaves. The process of leaf abscission is mainly regulated by abscisic acid and ethylene. Hence, this statement is also **incorrect**.

### Conclusion:
- The correct statements are **A** and **B**.
- The incorrect statements are **C** and **D**.

### Final Answer:
- Correct statements: **A** and **B**.

---