I believe the response would be D. Increasing the pH within the cell. This may be the case, because through changing the pH of the cell, the enzyme may form new unwanted interactions, which may affect the arrangement and the structure of the active site, which is will affect the ability of the maltose molecules to bind and undergo the breakdown into glucose molecules.
All enzymes work well or optimally within a given or particular pH. Going above or below will cause additional hydrogen bonds that might form, and other interactions affecting function.
