Which of the following are parts of the inner ear?

• A. Cochlea; basilar membrane; hair cells
• B. Tympanic membrane; ossicles
• C. Semicircular canals; utricle
• D. Pinna; auditory canal

Answer: (A)

The main idea is that hearing parts are located in the inner ear, with the cochlea as the key structure where sound is transformed into neural signals. Inside the cochlea, the basilar membrane moves in response to vibrating fluids, and the hair cells sitting on that membrane convert this mechanical motion into electrical signals that travel to the brain via the auditory nerve. This trio—cochlea, basilar membrane, and hair cells—together represents the core inner-ear elements directly involved in hearing.

Other options mix in structures from other parts of the ear or reference inner-ear components more related to balance than to hearing. The tympanic membrane and ossicles are in the middle ear and primarily transmit vibrations from the eardrum to the inner ear. The pinna and auditory canal are outer-ear structures that capture sound. While the semicircular canals and utricle are indeed in the inner ear, they belong to the vestibular system responsible for balance, not hearing.