Question: Waylon Smithers appeared an episode of The Simpsons that originally aired on January 21, 1990, and that has Homer promoted to what position?
Sentence (from "Who Shot Mr. Burns?"): Part One is the twenty-fifth and final episode of the sixth season and originally aired on the Fox network in the United States on May 21, 1995, while Part Two is the season premiere of the seventh season and aired on September 17, 1995.
Relevant evidence: No