What is the approximate make-up of inspired air?
- A$\text{CO}_2$ 0.04%, $\text{O}_2$ 16%, $\text{N}_2$ 78%, water vapour saturated
- B$\text{CO}_2$ 0.04%, $\text{O}_2$ 21%, $\text{N}_2$ 78%, water vapour variable
- C$\text{CO}_2$ 4%, $\text{O}_2$ 16%, $\text{N}_2$ 78%, water vapour saturated
- D$\text{CO}_2$ 4%, $\text{O}_2$ 21%, $\text{N}_2$ 78%, water vapour variable