CAM (Crassulacean Acid Metabolism)plants Such as Cacti Differ from Standard

CAM (crassulacean acid metabolism) plants such as cacti differ from standard C4 plants such as corn in which of the following ways?

A) CAM plants produce a 4-carbon molecule in the first step of carbon fixation,but C4 plants do not.
B) CAM plants are more efficient at producing sugar than C4 plants regardless of environmental conditions.
C) CAM plants are limited to producing CO₂ for the Calvin cycle during the day,while C4 plants produce CO₂ for the Calvin cycle both during the day and at night.
D) CAM plants minimize photorespiration whereas C4 plants do not.
E) CAM plants use both mesophyll and bundle sheath leaf cells for photosynthesis whereas C4 plants do not.