Answer
C.
Work Step by Step
Feedback inhibition allows for the whole metabolic pathway to be quickly turned down or shut off so as not to waste any resources when a final product is not needed. In this way, no resources are uselessly caught up in intermediates which are not being converted to final product, which would happen if B. or D. were true. If A. were true, the whole pathway would quickly shut down before making any real progress towards the final product of the pathway.
