Which of the following statements about the cyclic electron flow pathway of the light-dependent reactions is false?
a. Cyclic flow cannot by itself fuel the Calvin cycle because no NADPH is formed.
b. No proton gradient forms during cyclic flow.
c. Cyclic flow uses only photosystem I and does not use photosystem II.
d. Cyclic flow produces ATP in addition to those from the noncyclic flow to satisfy the ATP requirements of the Calvin cycle and other cell processes.