Question

gelatinous structure in the cochlea containing the hair cells that serve as auditory receptors
ampulla of corti
gonad of corti
organ of corti
coelom of corti
testis of corti

Explanation:

The organ of Corti is a crucial structure in the cochlea. It contains hair cells which are the auditory receptors. When sound waves cause vibrations in the cochlea, these hair cells are stimulated and convert the mechanical energy of sound into electrical signals that can be interpreted by the brain as sound. The ampulla is related to the semicircular canals (balance - related), gonad is related to reproductive organs, coelom is a body cavity in many animals, and testis is a male reproductive organ. None of these other options (ampulla of Corti, gonad of Corti, coelom of Corti, testis of Corti) have the function of containing auditory receptor hair cells in the cochlea.

Answer:

organ of Corti