Part A: The central idea of the text is best captured by the statement:
"News media has evolved to include a range of sources, but it continues to play an important role in informing citizens and holding public officials accountable."
Part B: The detail from the text that best supports this central idea is:
"People rely on the information they learn in the news to decide who to vote for and whether they approve of their current leaders and representatives." (Paragraph 7)
This detail underscores the role of news media in informing citizens and its impact on their political decisions and accountability.