Final answer:
In a cell, microtubules can be depolymerized by specific chemicals, but when given the choices of water, acid, base, or enzyme, enzymes are the correct option as they can catalyze the breakdown of microtubules.
Step-by-step explanation:
Microtubules (MTs) in a cell can be depolymerized by incubating the cell in colchicine, nocodazole, or other specific chemicals designed to interfere with the polymerization process. However, among the options provided, enzymes are the most relevant to the depolymerization of microtubules since enzymes can catalyze the breakdown of polymers into monomers. Hydrolysis is a common reaction in cellular metabolism, where it serves to break down polymers, including proteins, carbohydrates, and nucleic acids. Hydrolysis reactions are catalyzed by enzymes and acid or base conditions that may also affect the stability of proteins and nucleic acids.