The correct answer is: A. CAM plants
CAM plants are a type of plant that have a special way of photosynthesising. They open their stomata at night, when the air is cooler and there is less evaporation, and close them during the day to conserve water. This allows them to live in dry environments where other plants would not be able to survive.
C3 plants and C4 plants are two other types of plants that photosynthesize differently. C3 plants open their stomata during the day to take in carbon dioxide and release oxygen. C4 plants, on the other hand, open their stomata at night and close them during the day. This allows them to take in carbon dioxide more efficiently than C3 plants.
Succulent plants are plants that have thick, fleshy leaves that store water. They open their stomata during the day to take in carbon dioxide and release oxygen, but they close them at night to conserve water.
In conclusion, CAM plants are the only type of plant that open their stomata at night.