Final answer:
C) Two ATPs are needed per pair of electrons in the process of nitrogenase reductase.
Step-by-step explanation:
The answer to the question is c) Two.
Two ATPs are needed per pair of electrons in the process of nitrogenase reductase.
This is because nitrogenase reductase is an enzyme involved in the process of nitrogen fixation, where atmospheric nitrogen is converted into a usable form by reducing it to ammonia.
The reduction of nitrogen to ammonia requires the transfer of two electrons, and each electron transfer is coupled with the hydrolysis of one ATP molecule, resulting in a total of two ATPs needed per pair of electrons.