If a number of newspapers published stories exposing an elected official's acceptance of monetary bribes from a corporation in exchange for passing a particular law, it would be an example of the media serving in their role as A. a first branch. B. a judge and jury. C. a watchdog. D. a first estate.
The media is as described in the question playing the role of a watchdog. A watchdog is an individual/organization that plays a vital role in exposing corrupt and illegal practices that takes place in a society.