Mortimer Sellers (M.N.S. Sellers) (born 1959) is a law professor philosopher and historian. His work primarily concerns international law comparative law legal history constitutional law philosophy of law and Roman law. He has been Regents Professor of the University System of Maryland since 2003 the highest honor in the UM System. Sellers is best known for his books on republican constitutions global justice and universal human rights. 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