Final answer:
Buying up competing businesses is an example of horizontal integration. The correct answer is b.
Step-by-step explanation:
Buying up competing businesses in an industry is an example of horizontal integration. Horizontal integration occurs when a company grows by acquiring competitors within the same industry, thus consolidating the market and reducing competition.
This strategy contrasts with vertical integration, where a company expands by acquiring businesses along its supply chain, thereby controlling multiple aspects of a product's lifecycle. The famous American industrialist John D. Rockefeller implemented horizontal integration by merging with other oil companies or ousting competition to dominate the oil industry through his corporation, Standard Oil Company.
Antitrust laws are designed to prevent the creation of monopolies or oligopolies that can arise from practices like horizontal integration, by regulating or prohibiting mergers and acquisitions that could restrict market competition. Hence, the correct answer is B