What were joseph pulitzer and william randolph hearst well known pioneers of?

A. publishing news journals aimed at the upper soical classes in america.

B. producing weekly journals focused on world news

C. engaging in style of publishing called " yellow journalism".

D. working with missionaries to spread christianity in africa

C. engaging in a style of publishing called "yellow journalism"

Both men were newspaper publishers and in the late 19th century, their papers began to compete with each other. As a result they began to use "yellow journalism" (which is a lack of substantial, researched news combined with flashy headlines) to gain a larger readership.