Gas exchange in humans — practice question

Through what route does carbon dioxide leave the lungs?

• Aalveolus $\rightarrow$ bronchiole $\rightarrow$ bronchus $\rightarrow$ trachea
• Balveolus $\rightarrow$ bronchus $\rightarrow$ bronchiole $\rightarrow$ trachea
• Ctrachea $\rightarrow$ bronchiole $\rightarrow$ bronchus $\rightarrow$ alveolus
• Dtrachea $\rightarrow$ bronchus $\rightarrow$ bronchiole $\rightarrow$ alveolus