Which statement explains why desert plants close stomata during the day but open them at night?
A. Closing leaf stomata during the day and opening them at night makes the plants less vulnerable to attack by herbivores.
B. Stomata open at night because there is more carbon dioxide in the atmosphere available for photosynthesis and close during the day to prevent water loss.
C. Closing the leaf stomata during the day decreases the loss of water needed for photosynthesis while opening the stomata at night when the air is cooler allows the plant to take in and release gases.
D. Stomata open at night in order for the energy collected during the day to be used in several reactions and close during the day in order to release carbon dioxide during photosynthesis.

Stomata are pores localized in the plant epidermis whose function is to regulate gas exchange between plants and the atmosphere. Generally, stomata open during the day to allow the diffusion of carbon dioxide (CO2) and close during the night to avoid water loss (i.e., transpiration). On the other hand, CAM plants photosynthesize during the day, and exchange gases (CO2 and O2) during the night. Thus, desert CAM plants open their stomata during the night and close them during the day hours. These desert plants open stomata at night to absorb CO2 and close them during sunlight hours to prevent transpiration.