The correct option is A OAA
A) OAA - Oxalo Acetic Acid is the first product of the C4 pathway.
B) PGA is the first product of the C3 pathway.
C) PGA molecules are converted into PGAL by using ATP and NADPH from the light dependent reaction.
D) Dihydroxyacetone phosphate (DHAP) is the anion that is involved in many metabolic pathways, including the Calvin cycle in plants and glycolysis. It is the phosphate ester of dihydroxyacetone.
So the correct answer is 'OAA'.