Property A's return during the past 10 years are as followed: 2007 11% 2008 12% 2009 -5% 2010 -2% 2011 1% 2012 10% 2013 8% 2014 10% 2015 12% 2016 12% what is the average return of Property A? A. 5.9% B. 6.8% C. 6.90% D. 10%