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
Materials used for injection thyroplasty are ? 
Select and explain. 
A. Collagen, B. Acellular miconized human dermis, C. Gelatin powder, D. All the above
D: All the above
Answer: D: All the above 
Explanation: Ans. is 'd' i.e., All the above Injection thyroplasty accomplishes medicalization of the immobile vocal cord by injecting the cord directly to close an identified glottis gap. Many materials are currently used for injection thyroplasty including fat, fascia, gelatin powder, collagen, and miconized acellular human dermis.