Which mountain is higher than 20,000 feet?

Microsoft Rewards Bing Lightspeed Quiz: Which mountain is higher than 20,000 feet?

Mont Blanc
Denali
Mt. Adams
Mt. Rainier

The correct answer to this quiz is Denali.

Other correct answers are:
Annapurna
Broad Peak
Lhotse
Makalu

Please comment if you find a different answer.