Which of the following numbers is not an integer? ($$2015$$ Math Kangaroo Problem, Level $$7-8$$, Question \#$$6$$) 
选项为:A:$$\frac{2011}{1}$$  B:$$\frac{2012}{2}$$  C:$$\frac{2013}{3}$$  D:$$\frac{2014}{4}$$  E:$$\frac{2015}{5}$$  请回答其中一个选项.