IAA mainly inhibits growth of
The correct option is C Shoot
Auxins are growth promoting phytohormones. They help to initiate rooting in stem cuttings, an application widely used for plant propagation. They help to prevent fruit and leaf drop at early stages but promote the abscission of older mature leaves and fruits. In most higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called as apical dominance. Removal of shoot tips (decapitation) usually results in the growth of lateral buds. It is widely applied in tea plantations and hedge-making.