The Calcium Hydroxide Experiment Demonstrates That

The calcium hydroxide experiment demonstrates that

A) there is a much lower concentration of O₂ in expired air than in atmospheric air.
B) there is a much higher concentration of CO₂ in expired air than in atmospheric air.
C) there is a much higher concentration of O₂ in expired air than in atmospheric air.
D) there is a much lower concentration of CO₂ in expired air than in atmospheric air.
E) the concentrations of CO₂ in expired air and atmospheric air are approximately equal.