Natural cytokinins are synthesised in which regions of plants?
a)	Root apices	b)	Young fruit
c)	Developing shoot buds	d)	All of the above

(d)

Since the discovery of zeatin, several naturally occurring cytokinins and some synthetic compounds with cell division promoting activity have been identified. Naturally, cytokinins are synthesised in the regions where rapid cell division occurs like root apices, developing shoot buds, young fruit, etc.