The kindergarten student tells the school nurse that she can't hear out of her left ear. The nurse inspects the ear canal and sees a bright green object. Which condition does the nurse suspect? Select all that apply.

Pediatric unilateral hearing reduction commonly results from external auditory canal obstruction leading to impaired sound wave transmission to the tympanic membrane, producing conductive hearing loss due to mechanical blockage rather than cochlear or neural dysfunction processes. Rationale: A. Cerumen impaction involves accumulation of hardened earwax obstructing the external auditory canal. It can reduce hearing but does not specifically describe a visible bright green object. This condition is common but does not confirm foreign material presence. Therefore it is not the best match here. B. Presbycusis is age-related degenerative hearing loss affecting elderly patients due to cochlear hair cell degeneration. It does not occur in kindergarten-aged children. It is a bilateral progressive sensorineural process unrelated to acute unilateral obstruction or visible foreign object in ear canal. C. Sensorineural hearing loss results from cochlear or vestibulocochlear nerve damage affecting sound processing. It is not caused by visible external objects in the ear canal. There is no mechanical obstruction visible on inspection. Therefore it does not match the clinical finding described. D. Conductive hearing loss occurs when sound transmission is blocked in external or middle ear structures. A visible foreign object obstructing the canal directly prevents sound conduction. This produces unilateral hearing loss consistent with reported symptoms in pediatric patients. E. Foreign body obstruction is presence of external object in ear canal causing mechanical blockage. Bright green object strongly indicates inserted material such as toy fragment. This leads to acute unilateral hearing loss and is common in children due to exploratory behavior.