Which of the following is plant hormones ?

The correct answer is Option (4) → Cytokinin

Cytokinins are plant hormones, or phytohormones. They promote cell division, help in the growth of lateral shoots and delay the ageing of leaves, working alongside auxins, gibberellins, abscisic acid and ethylene.

Insulin, thyroxine and oestrogen are animal hormones, secreted by the pancreas, the thyroid and the ovaries respectively.