This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The monsaccharide glucose is best described by which one of the following  statements? 
Select and explain. 
A. It usually exists in the furanose form, B. It is a ketose, C. It possesses an anomeric C-2 carbon atom, D. It forms part of the disaccharide sucrose
D: It forms part of the disaccharide sucrose
Answer: D: It forms part of the disaccharide sucrose 
Explanation: Two monosaccharide units are linked by a glycosidic bond or yield 2 monosaccharide units on hydrolysis. Depending on their reducing property, they are divided into:

Nonreducing disaccharides: The functional groups are involved in the glycosidic bond formation, hence free functional groups are not available
Reducing disaccharides: Free functional groups are available.

Key Concept:

Glucose forms part of sucrose and is attached to fructose to form disaccharide i.e.,sucrose.