In the twentieth century, muckraking journalism developed mostly in response to a) wartime censorship. b) political corruption. c) nationalization of the press. d) decline of popular press magazine

The correct answer is:

B) political corruption.    

Muckrakers were reformist American journalists who denounced corrupt institutions and leaders and played a highly visible role during the Progressive Era period (1890s-1920s).

Muckraking magazines took on corporate monopolies and political machines while trying to raise public awareness and anger at urban poverty, unsafe working conditions, prostitution, cattle processing, and meat packing; patent medicines, and child labor.

As a result of their efforts, child labor laws were rewritten, food and medicine were protected for consumers and rules for fair business practices were established.