"The term $""$Value Chain"" reflects the fact that, as each step of this path is completed, the product becomes more valuable than it was at the previous step. Take for example the lumber business. Trees are transformed into usable wooden boards; the boards created from a tree can be sold for more money than the price of the tree. At what stage of the Value Chain is the lumber business the most valuable?"

When the trees have been planted

When the trees have been harvested

When the trees have been processed into usable wooden boards

When the seeds have been procured from suppliers

When the trees are no longer being planted