What gases are involved in the process of photosynthesis?

The process of photosynthesis involves two key components: carbon dioxide and water. During photosynthesis, plants take in carbon dioxide from the atmosphere through tiny openings in their leaves called stomata. They also absorb water through their roots. Using sunlight as energy, plants convert these two substances into glucose (a sugar) and oxygen. This transformation is crucial, as it not only provides energy for the plant's growth and development but also releases oxygen into the atmosphere, which is essential for most living organisms.

The combination of carbon dioxide and water serves as the foundational reactants for this process, making option D the correct choice. Understanding this process highlights the significant role that plants play in our ecosystem, acting as producers that contribute to the balance of gases in our atmosphere.