Answer:
A) oil
Explanation:
Ida Tarbell was a great American journalist who became known for revealing the unfair practices that were carried out by the Standard Oil Company.
During the presidency of Rockefeller, the company made deals with railway companies to form a monopoly, which would affect small entrepreneurs and lead to bankruptcy.
Thanks to the work of Ida Tarbell, in 1911 the company was taken to court by monopoly and was forced to divide into 34 small companies.
