Question: Who was a member of the IO theater and the host of a CBS talk program? 

Related documents: [0]  [DOC] iO, or iO Chicago, (formerly known as "ImprovOlympic") is an improv theater and training center in central Chicago, with a branch in Los Angeles called iO West. The theater both teaches and hosts performances of improvisational comedy. It was founded in 1981 by the late Del Close and Charna Halpern. The theater has many notable alumni, including Amy Poehler and Stephen Colbert. [END] 
[1]  [DOC] Stephen Tyrone Colbert ( , ; born May 13, 1964) is an American comedian, television host, actor, and writer. He is best known for hosting the satirical Comedy Central program "The Colbert Report" from 2005 to 2014, and hosting the CBS talk program "The Late Show with Stephen Colbert" beginning in September 2015. [END]  
Answer: Stephen Colbert
Stephen Colbert