Answer :
In the Calvin cycle, five ATP molecules are required to regenerate RuBP from five G3P molecules. Thus, option (II) is the correct answer.
In the Calvin cycle, there are three steps involved:
1. Carbon Fixation: In this step, the carbon molecule is fixed that is the Carbon atom from carbon dioxide is fixed by conjugation with RuBP. In this step, no ATP molecules are required.
2. Reduction: This step involves the reduction of the fixed carbon, into the formation of carbohydrates. This step requires 2 ATP for each G3P molecule.
3. Regeneration of RuBP: This step is used to regenerate the used RuBP molecule used in the first step which is the fixation of carbon. This step requires one ATP per G3P molecule.
Therefore, for 5 G3P molecules, we require 5 * 1 ATP which comes out to be 5 ATP molecules.
Learn more about the Calvin cycle:
https://brainly.com/question/920840
#SPJ4