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: Anaesthesia
Indications of tracheostomy are – a) Flail chestb) Head injuryc) Tetanusd) Cardiac tamponadee) Foreign body 
Select and explain. 
A. bcde, B. abcd, C. abce, D. abde
C: abce
Answer: C: abce 
Explanation: Flail chest due to multiple rib fracture, coma due to head injury, respiratory muscle spasm due tetanus and laryngeal foreign body are indications for tracheostomy.