The Americans were shocked by her account of John D. Rockefeller's terrible business practices, is the right answer.
Explanation:
Ida Tarbell was a muckraker, who presented Americans with aspects of corruption in industry and management. Ida Tarbell composed a set of essays to prove the corruption in Standard Oil to terminate the monopoly. Her account shocked the population of America with the terrible business practices of John D. Rockefeller.
