Which of the following is not an anti gibberellin or growth retardant?

Answer: Option D

Benzyl adenine is not an anti-gibberellin or growth retardant. It is a first-generation synthetic cytokinin that elicits plant growth and development responses, setting blossoms and stimulating fruit richness by stimulating cell division. It is an inhibitor of respiratory kinase in plants.
Gibberellin is a plant hormone found in seeds, young leaves and roots that cause excessive growth.