Natural cytokinins are produced in areas where rapid cell division occurs, including :

All of these

The correct answer is Option (4)-All of these

Cytokinins are a group of plant growth regulators which are primarily involved in performing cell division in plant roots, shoot system. This hormone helps in promoting the cell’s growth, development, differentiation, affecting apical dominance and delay in leaf senescence.

Cytokinins are plant growth hormones which are basic in nature, either amino purine or phenyl urea derivatives, that promote cytokinesis (= cell division) either alone or in conjunction with auxin.Kinetin, a synthetic cytokinin, is 6-furfuryl amino purine. Zeatin, a natural cytokinin, is 6-hydroxy 3-methyl trans 2-butenyl amino purine.

Natural cytokinins are synthesised in regions where rapid cell division occurs, for example, root apices, developing shoot buds, young fruits etc. It helps to produce new leaves, chloroplasts in leaves, lateral shoot growth and adventitious shoot formation.

Cytokinins help overcome the apical dominance. They promote nutrient mobilisation which helps in the delay of leaf senescence.