The length of a rectangle is increased by $10 \textbackslash\%$ and the width is decreased by $10 \textbackslash\%$. What percent of the old area is the new area? (2009 AMC 8, Question \#8) 
选项为:A:$$90$$  B:$$99$$  C:$$100$$  D:$$101$$  E:$$110$$  请回答其中一个选项.