The Reaction, 2 NH₄⁺ + α-Ketoglutarate + NADPH + ATP

The reaction, 2 NH₄⁺ + α-ketoglutarate + NADPH + ATP → glutamine + NADP⁺ + ADP + P_i + H₂O, is the combined result of what two enzymes?

A) first, glutamate synthase, then glutamate dehydrogenase
B) first, glutamate dehydrogenase ,then glutamine synthetase
C) first, glutamine synthetase, then glutamate synthase
D) first, glutamine synthetase, then glutamate dehydrogenase
E) none of the above