Which growth regulator is a substitute for low chilling treatment?

Answer: Option C

Gibberellin is the growth regulator which is the substitute for low chilling treatment.
Gibberellin is a hormone that replaces vernalization. Vernalisation is the process by which plants use a prolonged cold period in winter to promote flowering.
Gibberellin (GA) is the key plant hormone involved in regulating plant development. Thus, it is critical to elucidate the mechanism of the molecular regulation of vernalization and floral bud initiation to prevent premature bolting by the application of this hormone.