Source A: Excerpt from a historical biography

'John D. Rockefeller was a pivotal figure in the rise of American industry. His development of the Standard Oil Company revolutionized the oil industry and contributed significantly to America's economic growth during the late 19th and early 20th centuries.'

Provenance: Published biography of Rockefeller, 1920.

Source B: Excerpt from a business historian

'Rockefeller employed both innovative management strategies and aggressive tactics like rebates and buyouts to dominate the oil industry. These methods allowed him to control the market and eliminate competition.'

Provenance: A scholarly article on business practices of industrialists, 2005.

Source C: Editorial from a newspaper

'The rise of monopolies like Standard Oil threatens free competition and fair business practices. Government should intervene to protect consumers and small businesses.'

Provenance: Editorial published in a major newspaper, 1900.

Source D: Social commentator

'Rockefeller's immense wealth and business methods led to widespread debate about the ethics of capitalism and the power of big business in America.'

Provenance: Social commentary article, 1910.