In a 24-hour period, green plants continuously require and use carbon dioxide during photosynthesis. They take in carbon dioxide and release oxygen as a byproduct. However, plants also require oxygen for cellular respiration, which occurs both day and night.
So, the best answer from the options provided is: a. both carbon dioxide and nitrogen (although plants do not specifically require nitrogen continuously in the same manner as carbon dioxide and oxygen, they do need nitrogen as an essential nutrient for growth).
But given the choices focusing primarily on gas exchange during a 24-hour period, d. both carbon dioxide and oxygen would be the most accurate in the context of plants' metabolic processes.
1 answer