Query: Which CBS correspondant graduated from The Medill School of Journalism?
Context: The Medill School of Journalism has produced notable journalists and political activists including 38 Pulitzer Prize laureates. National correspondents, reporters and columnists such as The New York Times's Elisabeth Bumiller, David Barstow, Dean Murphy, and Vincent Laforet, USA Today's Gary Levin, Susan Page and Christine Brennan, NBC correspondent Kelly O'Donnell, CBS correspondent Richard Threlkeld, CNN correspondent Nicole Lapin and former CNN and current Al Jazeera America anchor Joie Chen, and ESPN personalities Rachel Nichols, Michael Wilbon, Mike Greenberg, Steve Weissman, J. A. Adande, and Kevin Blackistone. The bestselling author of the A Song of Ice and Fire series, George R. R. Martin, earned a B.S. and M.S. from Medill.