The correct option is A promotion of lateral branches
The phenomenon of apical dominance can be seen in most of the vascular plants in which, in the presence of apical bud, growth of lateral buds (formed just below the apex) is suppressed. At the removal of apical bud, the lateral buds grow vigorously. It shows that apical bud suppresses the growth of lateral bud (axillary bud) just below it. This is known as apical dominance. It is widely used in tea plantation and hedge making.