Sucrose needs to be hydrolyzed before it can show reducing properties because sucrose is a non-reducing sugar, which means it cannot reduce other compounds. Sucrose is a non-reducing sugar because it doesn't have a free aldehyde or ketone group. Thus, hydrolysis of sucrose is necessary in order to break the glycosidic bond between glucose and fructose(Sucrose) and convert them to free sugars that can show reducing properties. The correct answer is option C.