Final answer:
In C3 plants, the conservation of water promotes carbon fixation.
Step-by-step explanation:
In C3 plants, the conservation of water promotes carbon fixation. C3 plants refer to plants that use the Calvin cycle for carbon fixation, which is the process of converting atmospheric carbon dioxide into organic compounds like glucose. By conserving water, C3 plants can keep their stomata closed, reducing water loss and allowing them to continue the process of carbon fixation.