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
True about otoacoustic emissions -a) Are accousted by product of outer hair cellb) Are accousted by product of inner hair cellc) Used as a screening test of hearing in newborn infantd) Useful in ototoxicity monitoringe) Disappear in 8th nerve pathology 
Select and explain. 
A. acd, B. ad, C. bc, D. bde
A: acd
Answer: A: acd 
Explanation: None