Tests by air conduction are accomplished by placing earphones over the outer ears.Pure tone sound waves are carried through the outer ear and middle ear,converted to electrochemical energy in the inner ear and transmitted to the brain for processing by the auditory nerve.Four-year old Scott's air conduction test results for the right ear show thresholds of 40 dB HL @ 500 Hz,35 dB @ 1000Hz,and 35 dB @200 Hz.What may have happened along the air conduction pathway to produce these results?
A)Prenatal history of maternal rubella B)Meniere's disease C)A poorly functioning auditory tube D)None of the above