In the diagram, the structures used for offense and defense are labelled

In the diagram, structures used for offense and defense are labelled as i and ii. Structure i represents the canines, which are long and pointed teeth used for biting and tearing prey or for self-defense. They are prominent in carnivorous animals like lions, tigers, and wolves. Structure ii represents the horns, which are bony protrusions that grow from the heads of certain mammals like antelopes, cattle, and sheep. Horns are primarily used for defense against predators, rivals, and in some cases, for fighting over mates. Structures iii and iv are not associated with either offense or defense in this diagram. Structure iii represents the molars, which are broad teeth used for grinding food. Structure iv represents the nasal cavity, which is an air-filled space in the skull that connects the nostrils to the respiratory system.