The correct answer to this open question is the following.
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This scenario best illustrates forward integration.
This is a case of forward integration because BlockWood Inc., which was facing similar difficulties with other buyers too, eventually stopped supplying raw materials and took to manufacturing furniture instead. SO they decided to fabricate their own furniture.
Companies make this decision as a process of vertical integration to expand and grow their business. In this case to produce and control their own products, eliminating the retailer that had decided to pay less money for the raw materials.
So now, Blockwood Inc. has the challenge to design and sell the products it is fabricating.