Which of the following represent disaccharides?

Carbohydrates are classified based on the number of sugar units they contain. Disaccharides, often called "double sugars," consist of two monosaccharide molecules linked by a glycosidic bond [1]. Maltose and lactose are primary examples of disaccharides; maltose is formed by two glucose molecules, while lactose consists of glucose and galactose. In contrast, glucose and galactose are monosaccharides, which are single sugar units [1]. Starch and glycogen are polysaccharides, representing long chains of many monosaccharides used for energy storage in plants and animals, respectively [1]. Ribose and xylose are pentose sugars, which are five-carbon monosaccharides. Therefore, only the pair of maltose and lactose correctly represents disaccharides.

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1. [1] https://www.ncbi.nlm.nih.gov/books/NBK459280/