Which journalist's 'History of the Standard Oil Company' exposed the corruption of big business?

• A. Lincoln Steffens
• B. Jacob Riis
• C. Upton Sinclair
• D. Ida Tarbell

Answer: (D)

Investigative journalism that exposes how large firms operate and bend markets drives public awareness and reform. Ida Tarbell’s History of the Standard Oil Company is the classic example: she unraveled how John D. Rockefeller’s Standard Oil used ruthless tactics to dominate the industry, including secret railroad rebates, price manipulation, and trust arrangements to squeeze competitors. Her careful use of company records and other documents built a powerful, evidence-based portrait of big-business corruption, fueling public support for antitrust action and helping pave the way for the 1911 Supreme Court decision to break up Standard Oil. The other journalists mentioned focused on different reform targets—political corruption, urban poverty, or unsafe meatpacking—rather than exposing a monopoly in the way Tarbell did, which is why this choice fits the prompt.