In which of the following does not net gaseous exchange take place between leaves and the atmosphere?

Explanation

At dawn and dusk, the intensity of light is low. At this moment the amount of oxygen released from photosynthesis is equal to the amount of oxygen used in respiration. Similarly, the amount of carbon dioxide released from respiration is equal to the amount of carbon dioxide in photosynthesis. It is called "Compensation Point." Hence, option C is correct.