12. A person who can only perceive low-frequency sounds but has lost the ability to hear high-frequency sounds likely has a structural abnormality in which part of the auditory system? (A) Damage or scarring of the tympanic membrane (eardrum) due to chronic infections. (B) Uniform stiffening of the entire basilar membrane. (C) Abnormal thickening of the auditory ossicles (malleus, incus, and stapes). (D) Detachment of the tectorial membrane from the organ of Corti. (E) Loss of hair cell function in all regions of the basilar membrane except the apex.