Robert Leo Prestel (born February 11 1936) is an American intelligence official and mathematician who was Deputy Director of the National Security Agency from 1990 to 1994 during which time he was the highest ranking civilian in the agency. Prestel joined the NSA in 1962 and held many positions prior to being appointed as deputy director including Director of Education and Training from Deputy Director for Research and Engineering. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Office Holder