The correct answer is A) cellulose.

Explanation:

• Cellulose is a polysaccharide, meaning it is a carbohydrate composed of long chains of monosaccharide units (in this case, glucose molecules) linked together. It is a primary structural component of plant cell walls.
• Galactose (B) and glucose (C) are monosaccharides, which are simple sugars consisting of a single sugar molecule.
• Sucrose (D) and lactose (E) are disaccharides made up of two monosaccharide units linked together. Sucrose is composed of glucose and fructose, while lactose consists of glucose and galactose.

Therefore, cellulose is the only polysaccharide among the options provided.

Answer: A) cellulose