Which of the Following Correctly Defines Apex

Which of the following correctly defines apex?

A) The membrane covering the oval window transmits vibration into the cochlea through this fluid.
B) Bends in response to vibrations of the cochlear fluid and serves to elicit neural activity in the hair cells.
C) A nerve where a branch is formed by axons from the cochlear nerve.
D) A band of subcortical white matter located between Broca's area and Wernicke's area.
E) Near this point, the basilar membrane is more flexible, and the receptors located here are exposed to vibrations of lower frequencies.