In Addition to Permitting Gas Exchange,stomata Allow Water to Evaporate

In addition to permitting gas exchange,stomata allow water to evaporate from plant cells.This suggests that a plant,in order to maximize photosynthesis without dehydrating,would typically keep its stomata

A) open day and night.
B) closed day and night.
C) open during daylight and closed at night.
D) open at night and closed during daylight.
E) open when the cell is high in CO₂ and closed when it is low in CO₂.