Question

how did muckrakers contribute to the progressive era? by promoting isolationist foreign policies. by supporting political machines. by advocating for laissez - faire economic policies. by exposing corruption and social problems through investigative journalism

Explanation:

Muckrakers were journalists in the Progressive - Era who used investigative journalism to expose issues like corruption, unfair business practices, and social problems. Their work raised public awareness and spurred reform efforts.

Answer:

By exposing corruption and social problems through investigative journalism