In her final press conference, Federal Reserve Chair Janet Yellen answers questions about tax policy and inflation. » Subscribe to CNBC: http://cnb.cx/SubscribeCNBC About CNBC: From 'Wall Street' to 'Main Street' to award winning original documentaries and Reality TV series, CNBC has you covered. Experience special sneak peeks of your favorite shows, exclusive video and more. Connect with CNBC News Online Get the latest news: http://www.cnbc.com/ Find CNBC News on Facebook: http://cnb.cx/LikeCNBC Follow CNBC News on Twitter: http://cnb.cx/FollowCNBC Follow CNBC News on Google+: http://cnb.cx/PlusCNBC Follow CNBC News on Instagram: http://cnb.cx/InstagramCNBC Federal Reserve Chair Janet Yellen: Personally Concerned About US Debt | CNBC