For the metabolic reaction depicted in the second to last slide of the video, with enzymes 1, 2, and 3 sequentially producing products B, C, and D starting with substrate A, what would happen if product D were an inhibitor of enzyme 3 (the enzyme that produces D from C)?

a. The pathway would run normally
b. A would build up
c. B would build up
c. C would build up
e. D would build up