Given the question: Answer the following question given this paragraph: Functionally, the respiratory system can be divided into a conducting zone and a respiratory zone. The conducting zone of the respiratory system includes the organs and structures not directly involved in gas exchange. The gas exchange occurs in the respiratory zone. Q: The conducting zone of the respiratory system includes the organs and structures not directly involved in what? Choices: - copper exchange - helium exchange - gold exchange - gas exchange A:
The answer is:
gas exchange