What effect did ida Tarbells book have?

Explanation:

Tarbell's exhaustive study not only gave rise to a new style of investigative journalism sometimes referred to as muckraking but also was instrumental in the 1911 dismantling of the Standard Oil Company behemoth, which was determined to be in violation of the Sherman Antitrust Act. Through her achievements, she not only helped to expand the role of the newspaper in modern society and stimulate the Progressive reform movement, but she also became a role model for women wishing to become professional journalists.

if i am correct the answer is going to be a) the federal program of reconstruction ended.