The Concentration of CO₂ in Earth's Atmosphere Has Increased Over

Multiple Choice

The concentration of CO₂ in Earth's atmosphere has increased over the past 200 years. If this trend continues, as seems likely, what could happen to photosynthesis? Ignore global warming and assume that the content of oxygen in the atmosphere will not change.

A) The net yield C₃ photosynthesis should increase; C₄ photosynthesis should be unaffected.
B) The net yield C₃ photosynthesis should decrease; C₄ photosynthesis should be unaffected.
C) The net yield C₃ photosynthesis should stay the same; C₄ photosynthesis should increase.
D) Both the net yield C₃ photosynthesis and C₄ photosynthesis should not change.
E) None of the above