The correct option is A Nishida
Scotoactive stomata are the stomata, which open in dark and close during the day time. Scotoactive stomata occur in succulents, e.g., cactus and bryophyllum. Succulents perform crassulacean acid metabolism or CAM in their photosynthesis. Nishida explained in succulents during night there is accumulation of organic acids, whereas during day time the organic acids breakdown releasing carbon dioxide, which keeps stomata closed. During night, because of formation of organic acids carbon dioxide is consumed and concentration of carbon dioxide is less.