The practice that allows larger companies to purchase smaller companies to increase profitability or eliminate competition is "acquisitions" (option a).
Acquisitions involve one company buying another, either through a stock purchase or asset purchase. This strategic move allows the acquiring company to gain control of the target company's assets, technology, customer base, or market share.
By absorbing smaller competitors, larger companies can achieve economies of scale, synergies, and eliminate competition, ultimately contributing to increased profitability and market dominance.
This contrasts with other options like LLCs (Limited Liability Companies), IPOs (Initial Public Offerings), or buybacks, which are not directly related to the acquisition of other companies for strategic purposes.