- A Ethylene
- B Gibberellin
- C Auxin
- D Cytokinin
Correct answer: A. Ethylene
Explanation: Ethylene, a gaseous plant hormone, is well known for promoting fruit ripening as well as causing leaf senescence and abscission.
Concept context
Phases of plant growth, the five classical plant hormones plus newer ones, photoperiodism, vernalization, and seed dormancy.