Explanation:

- Inulin is primarily a polymer of fructose.

- ?? Correct Answer: Fructose ??

- Inulin is a type of soluble dietary fiber found in many plants.

- It consists mainly of fructose units linked together.

- Option 1: Glucose

- Glucose polymers include starch and glycogen.

- Not related to inulin.

- Option 2: Galactose

- Galactose is a component of lactose, found in milk.

- Not involved in inulin structure.

- Option 4: Arabinose

- Arabinose is a monosaccharide found in hemicelluloses.

- Not a building block of inulin.