In the process of carbon fixation, RuBP attached a CO2 to produce a 6 carbon molecule, which is split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle?
A. Addition of a pair of electron from NADPH
B. inactivation of RuBP caroxylase enzyme
C. Regeneration of ATP fro ADP
D. regeneration of rubisco
E. A gain of NADPH
Answer: D