**Core Concept**
Inulin is a type of fructan, a class of polysaccharides composed of fructose units. It is commonly found in plants such as chicory, artichokes, and asparagus, serving as a storage carbohydrate.

**Why the Correct Answer is Right**
Inulin is a polymer of fructose molecules, specifically a fructan composed of a chain of β-2,1-fructose units. This unique structure allows inulin to be a soluble fiber in the digestive system, where it can be fermented by gut bacteria to produce short-chain fatty acids. The β-2,1-glycosidic bond between fructose units is a key feature of inulin's structure and function.

**Why Each Wrong Option is Incorrect**
**Option A:** This is not correct because inulin is not a polymer of glucose molecules. Glucose is a monosaccharide that is not typically found in fructans.
**Option B:** While inulin is related to fructose, it is not a polymer of mannose molecules. Mannose is a different type of sugar that is not typically found in fructans.

**Clinical Pearl / High-Yield Fact**
Inulin is an example of a prebiotic fiber, which means it can help feed beneficial gut bacteria and promote a healthy gut microbiome. This can have a range of benefits for overall health, including improved digestion and immune function.

**Correct Answer: B. Fructose**