Answer:
e. The inhibitor is a reversible inhibitor.
Step-by-step explanation:
The reason for which the enzyme has more activity after the chromatography step is that the enzyme was separated from the inhibitor.
The enzyme and the inhibitor could only be separated by size-exclusion chromatography if they had different sizes (which is tipically the case between enzymes and inhibitors) and the inhibitor was a reversible one.
When mixed together, the inhibitor was bonded to the enzyme.