What industry did ida tarbell target? Apex

the oil industry

The Standard Oil Company, is the right answer.

Explanation:

Ida Minerva Tarbell was an investigative reporter, writer, lecturer and biographer from America. She was a popular muckraker of the Progressive Era during the later phase of the 19th and the early phase of the 20th Century. She is well known for her work "The History of the Standard Oil Company" that got published in the year 1904. She made her focus on the monopoly of Standard Oil Company.