CAM Plants Keep Stomata Closed in Daytime, Thus Reducing Loss

Multiple Choice

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.
B) fix CO₂ into sugars in the bundle-sheath cells.
C) fix CO₂ into pyruvate in the mesophyll cells.
D) use the enzyme phosphofructokinase, which outcompetes rubisco for CO₂.
E) use photosystem I and photosystem II at night.