How does the energy consumption of the Calvin cycle reflect its efficiency in producing sugars?

• A. The Calvin cycle does not require ATP or NADPH, making it energy-neutral.
• B. The Calvin cycle is highly efficient, using minimal energy to produce sugars.
• C. The Calvin cycle is energy-intensive, requiring 9 ATP and 6 NADPH to produce one sugar molecule, indicating a high energy cost for sugar production.
• D. The Calvin cycle produces more energy than it consumes, making it an energy-generating process.