Option D is correct because the textbook context explicitly identifies Cytokinins as plant hormones. The text states that 'Cytokinins promote cell division' and they are 'present in greater concentration in areas of rapid cell division, such as in fruits and seeds.' The context further clarifies that 'These are examples of plant hormones that help in promoting growth.' Other plant hormones mentioned in the context include auxin, gibberellins, and abscisic acid. Options A (Insulin), B (Thyroxin), and C (Oestrogen) are not mentioned as plant hormones anywhere in the provided context.