Question: Which family does the writer particularly discussed about their political activities in his book Dark Money?
Sentence (from "Dark Money (book)"): Dark Money: The Hidden History of the Billionaires Behind the Rise of the Radical Right (2016) is a non-fiction book written by the American investigative journalist Jane Mayer, about a network of extremely wealthy conservative libertarians, foremost among them Charles and David Koch, who have together funded an array of organizations that work in tandem to influence academic institutions, think tanks, the courts, statehouses, Congress, and the American presidency for their own benefit.
Relevant evidence: Yes