Read this: Arsenal finished in either first or second place in the league in eight of Wenger's first eleven seasons at the club, although on no occasion were they able to retain the title. As of July 2013, they were one of only five teams, the others being Manchester United, Blackburn Rovers, Chelsea, and Manchester City, to have won the Premier League since its formation in 1992. Arsenal had never progressed beyond the quarter-finals of the Champions League until 2005–06; in that season they became the first club from London in the competition's fifty-year history to reach the final, in which they were beaten 2–1 by Barcelona. In July 2006, they moved into the Emirates Stadium, after 93 years at Highbury.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): Who did Arsenal compete against in the 2005-06 Championship League?
unanswerable