I think it is B because the other ones makes sense
A 31-year-old patient tells the nurse that he has noticed a progressive loss in his hearing. he says that it does seem to help when people speak louder or if he turns up the volume. the most likely cause of his hearing loss is :
Otosclerosis is a common cause of conductive hearing loss in young adults between the ages of 20 and 40 years.
You can only see it if you use a microscope and you cannot taste it or smell it