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
True about Heliox – a) Helium is an inert gasb) Less viscous than airc) Higher density than aird) Reduces work of breathinge) Mixture of He & O2 
Select and explain. 
A. acd, B. ade, C. abd, D. ad
B: ade
Answer: B: ade 
Explanation: Heliox is a mixture of helium (80%) and oxygen (20%). Heliox has a similar viscosity to air but a lower breathing and lowers airway resistance.
Helium is an inert gas.