Understand the key terms

• A non-reducing sugar does not reduce Tollens' or Fehling's reagent.
• On hydrolysis, if it gives two reducing monosaccharides, we need a disaccharide whose component monosaccharides are reducing.

Check the options

A. Fructose

• Fructose is a monosaccharide, not a disaccharide.
• It does not hydrolyse into two monosaccharides.
• Hence, not correct.

B. Galactose

• Galactose is also a monosaccharide.
• It cannot hydrolyse into two monosaccharides.
• Hence, not correct.

C. Glucose

• Glucose is a monosaccharide.
• It also cannot hydrolyse into two monosaccharides.
• Hence, not correct.

D. Sucrose

• Sucrose is a disaccharide made of glucose + fructose.
• It is non-reducing because both anomeric carbons are involved in the glycosidic linkage.
• On hydrolysis: $\text{Sucrose} + H_2O \rightarrow \text{Glucose} + \text{Fructose}$
• Both glucose and fructose are reducing monosaccharides.
• Hence, correct.

Conclusion

The non-reducing sugar that hydrolyses to give two reducing monosaccharides is: $\boxed{\text{Sucrose}}$

Comparison with stored answer

• Derived answer: D
• Stored correct answer: D
• They match.