Answer:
The correct answer is An inhibitor is being used in reaction B. See the explanation below, please.
Explanation:
Inhibitors are substances that bind in the enzyme sector where the substrate would bind. In the case of B, it binds to the enzyme in question, generating a lower enzyme-substrate concentration. There are competitive inhibitors (the inhibitor binds at a different site to the active site and the substrate can bind) and non-competitive (the inhibitor binds to the enzyme, preventing enzyme-substrate formation).
