What were muckrakers known for during the Progressive Era?

Muckrakers were prominent figures during the Progressive Era known for their investigative journalism that aimed to expose societal issues, corruption, and injustices in various sectors, including politics, business, and social practices. By utilizing their writing skills, these journalists brought to light the often-hidden problems of urbanization, industrialization, and political corruption, raising public awareness and prompting calls for reform. Their work played a crucial role in advancing the Progressive movement, leading to significant changes in policies and regulations aimed at improving the social fabric of the nation.

For instance, muckrakers like Upton Sinclair exposed unsanitary conditions in the meatpacking industry through his novel "The Jungle," contributing to the passage of the Pure Food and Drug Act. Similarly, Ida Tarbell's investigations into the monopolistic practices of Standard Oil helped spur trust-busting efforts by the government. This focus on investigation and reform exemplified the muckrakers' crucial role in the Progressive Era, making option B the correct answer.