How much net gain of G3P is obtained after one calvin cycle?

Explanation

The Calvin cycle, also referred to as the C3 cycle, processes CO2 into carbohydrates in the stroma of chloroplasts. Each cycle fixes three CO2 molecules to produce six G3P molecules. However, five G3P molecules are recycled to regenerate RuBP, the molecule that captures CO2, thus allowing the cycle to proceed. As a result, only one G3P is a net gain for further carbohydrate synthesis. This is why the net gain of G3P after one Calvin cycle is one. The other options incorrectly assume a higher net gain due to a misunderstanding of the cycle's regeneration process.