Refer to the Figure Showing the CO₂ Uptake in Soybean

Multiple Choice

Refer to the figure showing the CO₂ uptake in soybean leaves in response to increasing O₂ concentration for soybean leaves exposed to two different CO₂ levels.
Based on the figure, the best explanation for the relationship of CO₂ uptake and O₂ concentration is that

A) CO₂ uptake increases with increasing O₂ concentration at both CO₂ levels.
B) CO₂ uptake decreases with increasing O₂ concentration at both CO₂ levels.
C) CO₂ uptake becomes negative by 100% O₂ concentration at both CO₂ levels.
D) CO₂ uptake becomes negative by 100% O₂ concentration at high CO₂ levels.