The process by which carbon from CO₂ is incorporated into organic molecules:

Explanation

The correct answer is the Calvin cycle, which is the light-independent process of photosynthesis where carbon dioxide is fixed into organic molecules like glucose. The Calvin cycle takes place in the stroma of chloroplasts and uses ATP and NADPH produced during the light-dependent reactions. In contrast, glycolysis is a part of cellular respiration and does not involve CO₂ fixation. The Krebs cycle is another cellular respiration process that occurs in mitochondria, not related to photosynthesis. The light-dependent reactions provide the energy carriers needed for the Calvin cycle but do not themselves incorporate carbon.