Final answer:
John D. Rockefeller's business beliefs align with the idea of 'Survival of the fittest,' as he focused on reducing competition and controlling the market to ensure the dominance of his enterprises.
Step-by-step explanation:
The phrase summarizes John D. Rockefeller's personal beliefs about business most accurately with option C) Survival of the fittest. This concept draws on the notion that in business, as in nature, entities that are better adapted to their environment will prevail over those that are less so. Rockefeller’s approach to business was characterized by the integration of various aspects of the industry (horizontal and vertical integration) and the formation of trusts, aiming to reduce competition and establish control over the market.