The correct option is "a and c only":
Hydrolysis involves water molecules as a substrate and the breakdown of polymers. During hydrolysis, a water molecule is used to split a larger molecule into two smaller molecules. This is the opposite of condensation, which involves the removal of water to join two smaller molecules into a larger one.
Therefore, option (a) is correct, while options (b) and (c) are incorrect. Option (d) is incorrect because it includes option (b) which is incorrect.