The correct option is C cytokinin
Cytokinin is responsible for cell division leading to cell growth, elongation and differentiation. It prevents apical dominance and delays leaf senescence by promoting nutrient mobilisation.
Auxin is responsible for stem elongation, inhibition of lateral buds or maintenance of apical dominance.
Gibberellic acid is responsible for stem elongation, germination, flowering and fruit ripening.
Ethylene is responsible for fruit ripening.