Final answer:
Amazon's acquisition of Whole Foods represents horizontal integration, as both companies operate at the same level in the retail industry.
Step-by-step explanation:
When Amazon acquired Whole Foods, this was an example of horizontal integration. Horizontal integration occurs when a company acquires another company that operates at the same level of the value chain in an industry. In this case, both Amazon and Whole Foods are retailers, though Amazon is more diversified. The acquisition thus consolidates their positions in the retail market, particularly in the organic and premium food segments.
This is different from vertical integration, where a company might acquire another company involved in a different stage of production or supply chain, such as a manufacturer or supplier. It also is not collusion, where companies might secretly agree to work together to manipulate the market rather than merging, nor is it conglomerate integration, where unrelated businesses become part of a single corporation.