This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
In a case of bilateral hearing loss, what should be done-a) Stapedectomyb) Cochlear implantc) Hearing aid bone implant d) Sodium fluoride 
Select and explain. 
A. abc, B. acd, C. bcd, D. abcd
D: abcd
Answer: D: abcd 
Explanation: None