The correct answer is option B, that is, production of glucose in plants.
The conversion of carbon dioxide and water to produce energy (glucose) in the presence of sunlight, while discharging oxygen as a byproduct is known as photosynthesis.
In the process of photosynthesis, 6 molecules of carbon dioxide react with 6 molecules of water in the presence of sunlight and generate 1 molecule of glucose and 6 molecules of oxygen.
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂