Final answer:
Galactose is the monosaccharide among the given options. Cellulose and starch are examples of polysaccharides. Lactose is formed by a glycosidic bond between glucose and galactose, and C6H12O6 represents a hexose monosaccharide.
Step-by-step explanation:
The carbohydrate that is a monosaccharide among the options provided is galactose (option b). Monosaccharides are the simplest form of carbohydrates and they include glucose, fructose, and galactose, all of which have the same chemical formula C6H12O6 but differ in structure. The other options, sucrose (option a), maltose (option c), and lactose (option d), are all disaccharides, which means they are composed of two monosaccharides linked together.
Moreover, cellulose and starch are examples of polysaccharides (d). Polysaccharides are long chains of monosaccharides linked together. A glycosidic bond joins the molecules in the disaccharide lactose (b), which is formed from glucose and galactose. Additionally, C6H12O6 is the formula for a hexose monosaccharide (c).