In the Initial Step in Carbon Fixation, a Molecule of CO₂

In the initial step in carbon fixation, a molecule of CO₂ is attached to RuBP to produce a six-carbon molecule, which is immediately split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P) , what more needs to occur to complete the Calvin cycle?

A) addition of a pair of electrons from NADPH
B) regeneration of ATP from ADP
C) regeneration of RuBP
D) regeneration of NADP⁺