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: Unknown
A double lumen tracheostomy tube all are true EXCEPT: 
Select and explain. 
A. Easy to remove inner cannula, B. Easy to clean inner cannula, C. Easy to replace inner cannula, D. No inner cannula
D: No inner cannula
Answer: D: No inner cannula 
Explanation: ANSWER: (D) No inner cannulaREF: Dhingra 4th ed p. 414Double lumen tracheostomy tubes have an inner cannula inside an outer cannula. It is easier to remove, clean and replace the inner cannula.