Answer: Water
Explanation:
Hydrolysis is the process by which bond between the macromolecules splits by the addition of water. This process is catalysed is enzymes.
Most of the macromolecules like carbohydrates, protein, fat inside the human body is broken down by the help of water only.
WE can say that polymer is broken into monomer by the help of water.
Thus, the correct answer is Water.