Question: What episode of South Park, aired on April 21, 2010, started the "Draw Mohammed Day" event? 
Sentence (from "Everybody Draw Mohammed Day"): It stemmed from a protest against censorship of the American television show "South Park" episode "201", led by the show's distributor Comedy Central, in response to death threats that had been made against some of those responsible for two segments broadcast in April 2010.
Relevant evidence: No