Question: Rolf Pfeifer is currently a visiting professor at a university located in which country ?
Sentence (from "Achille Mbembe"): He was Assistant Professor of History at Columbia University, New York, from 1988-1991, a Senior Research Fellow at the Brookings Institution in Washington, D.C., from 1991 to 1992, Associate Professor of History at the University of Pennsylvania from 1992 to 1996, Executive Director of the Council for the Development of Social Science Research in Africa (Codesria) in Dakar, Senegal, from 1996 to 2000.
Relevant evidence: No