Question: The Unknown Known, is a 2013 American documentary film about the political career of former U.S. Secretary of Defense and congressman Donald Rumsfeld, an American retired politician and businessman, heserved as the 13th Secretary of Defense from 1975 to 1977 under which President?  
Sentence (from "The Unknown Known"): The Unknown Known (also known as The Unknown Known: The Life and Times of Donald Rumsfeld) is a 2013 American documentary film about the political career of former U.S. Secretary of Defense and congressman Donald Rumsfeld, directed by Academy Award winning documentarian and filmmaker Errol Morris.
Relevant evidence: Yes