Final answer:
The correct answer is option 1. The term 'muckrakers' was coined by Teddy Roosevelt to describe journalists who exposed corruption within industry and government during the Progressive Era, leading to significant legislative changes.
Step-by-step explanation:
The phrase coined by President Theodore Roosevelt to define reporters who uncovered corruption within industry and government during the Progressive Era is muckrakers. These individuals conducted in-depth investigations into societal issues, including corrupt politics and business practices, poor working conditions, and unsanitary living conditions.
Their work, often published in newspapers and journals, played a crucial role in shaping public opinion and driving legislative changes aimed at reforming and regulating businesses and government, such as the Pure Food and Drug Act of 1906. The term muckrakers was meant to be derogatory, echoing a character from John Bunyan's The Pilgrim's Progress who was fixated on raking filth and could not look up to heaven, but it has since become associated with a noble journalistic tradition.