Answer:
X is a competitive inhibitor.
Step-by-step explanation:
X is a competitive inhibitor because it fights with the substrate for the active site of the enzyme. The active site is specific for a type of substrate, but as the inhibitor has a similar structure to the substrate, it can fit and not allow the substrate to interact with the enzyme and make its reaction. What we can do to do to keep having enzyme-substrate bindings is add more substrate to the solution, so there are more substrates than inhibitors, which leads to more products as a final result of the interaction between the enzyme and the substrate.