Final answer:
The breakdown of sucrose into glucose and fructose with the addition of water is a hydrolysis reaction, not a combustion, displacement, or synthesis reaction. The correct option is c).
Step-by-step explanation:
The reaction in question, C12H22O11 + H2O → C6H12O6 + C6H12O6, involves the breakdown of the disaccharide sucrose into two monosaccharides, glucose and fructose, with the addition of water.
This process is known as hydrolysis, where a water molecule is used to break the bond between the monosaccharides.
Therefore, the correct answer to the student's question is: The hydrolysis of the sugar sucrose to the sugars glucose and fructose is a hydrolysis reaction. This excludes the options for a combustion, displacement, or synthesis reaction. Option c) is the correct one.