Which was an effect of muckraker ida tarbell's writing?

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.

very positive impact on our industries in the west, sine they promoted settlement and increased the ways in which goods could be transported to market.  

populist movement, in u.s. history, politically oriented coalition of agrarian reformers in the middle west and south that advocated a wide range of economic and political legislation in the late 19th century. thus in 1892 their leaders organized the populist, or people's, party, and the farmers' alliances melted away.