A growing plant is building new cell walls. Which substance does it make from its glucose for that job?

Explanation

Cell walls are built from long chains formed by joining sugar units together, so the raw material for them is the sugar the leaf produced, and cellulose is the name of that wall material. Protein is the tempting answer, but proteins also need nitrogen taken up as mineral ions and cannot be built from sugar alone; starch is a chain of the same sugar units serving a different purpose, storage rather than structure; and the green pigment is not a building material of the wall at all.