Which of the following is not an inhibitory substance governing...

Some seeds fail to germinate even when external conditions are favorable. Such seeds are dormant and are controlled by endogenous conditions within the seed itself. Impermeable and hard seed coat; phenolic acids, para-ascorbic acid; immature embryos, and the presence of chemical inhibitors such as abscisic acids are some reasons which cause seed dormancy. The effect of such inhibitory substances can be removed by the application of certain chemicals like gibberellic acid and nitrates or by subjecting the seeds to chilling conditions.