50.
A:
Conversion of 3 phosphoglycerate into glyceraldehyde 3 phosphate
B:
Utilisation of CO2 to produce 3 phasphoglycerate
C:
Conversion of glyceraldehyde 3 phoshpate into ribulose 5 phosphate
D:
Carboxylation of phosphoenol phuvate to oxalocetate
The answer is: D