Please answer the following question: John M. Walker Jr. - John Mercer Walker Jr. (born December 26 1940) is a judge of the United States Court of Appeals for the Second Circuit. He was appointed to the Second Circuit in 1989 and served as the Circuit's chief judge from October 1 2000 to October 1 2006 when he assumed senior status.He was a judge in the United States District Court for the Southern District of New York appointed in 1985 by President Ronald Reagan before being elevated to the Second Circuit in 1989. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Office Holder