Polysaccharides are characterized by:

Polysaccharides are primarily characterized by being composed of long chains of many sugar molecules. This structural feature distinguishes them from other types of carbohydrates, such as monosaccharides, which consist of a single sugar unit, and disaccharides, which are made up of two sugar units. The long chains can be branched or unbranched and are formed through the process of glycosidic bonding between multiple monosaccharide units. Common examples of polysaccharides include starch, glycogen, and cellulose, all of which play various roles in energy storage and structural integrity in living organisms.

The other options do not accurately define polysaccharides. For instance, while some polysaccharides can be soluble in water, many of them, such as starch and cellulose, are not soluble and thus do not fit this characteristic universally. Likewise, polysaccharides do not consist of a single sugar unit, which is a defining trait of monosaccharides. Lastly, while they can provide energy, particularly when broken down into simpler sugars, this is not their immediate function, contrasting with monosaccharides, which do provide immediate energy.