Which choice lists the structures adapted for permitting air flow from the external environment to the human lungs in the correct order?

Well, it all starts with the mouth, which contains the nasal cavity which is the first destination. Which then caries into the throat where the trachea is and the only option with that is B. So, I would say B would be your correct answer, just google a picture of the respiratory system. Hope this helps in the near future.

~I hope this helped!

I am, yours most sincerely,
Joshua A. Bunn