CAM Plants Keep Stomata Closed in Daytime, Thus Reducing Loss

CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they

A) fix CO₂ into organic acids during the night when temperatures are cooler.
B) fix CO₂ into organic acids in the bundle-sheath cells, which do not rely on stomata.
C) fix CO₂ into organic acids in the mesophyll cells, which do not rely on stomata.
D) fix CO₂ into by combining it with RuBP in the Calvin cycle.
E) obtain CO₂ through their roots during the day.