What Advantage Is It for Some Plants to Use C₄

What advantage is it for some plants to use C₄ and CAM photosynthesis?

A) They can conserve water and reduce photorespiration under hot, dry conditions
B) They can conserve water and produce four-carbon sugars instead of glucose
C) They can absorb carbon dioxide more efficiently when atmospheric CO₂ levels are low.
D) They can use the Calvin cycle at night when conditions are cooler and more humid.