Step 1: Understanding the Question:
This question tests knowledge of grape physiology and plant growth regulators.
Step 2: Detailed Explanation:
Berry elongation in grapes (A): Promoted by GA3 (II).
Single Sigmoid Curve (B): Observed in Malus domestica (apple) (III).
Induce rooting (C): Using IBA (I).
Veraison stage in grape (D): Onset of ripening (IV).
Thus, the correct matching is A-II, B-III, C-I, D-IV.
Step 3: Final Answer:
Thus, the correct answer is A-II, B-III, C-I, D-IV, which corresponds to option (D).
[0.5cm]