Final answer:
The structure shown in the figure is the cochlea. It is responsible for hearing as sound is transduced into neural signals by sensory receptor cells called hair cells.
Step-by-step explanation:
The structure shown in the figure is the cochlea.
The inner ear consists of the bony and membranous labyrinth, and the cochlea is part of the membranous labyrinth. It is responsible for audition, or hearing. Within the cochlea, sound is transduced into neural signals by sensory receptor cells called hair cells.
Therefore, the correct answer is 1) Cochlea.