如果$$a=\frac{19}{27}$$，$$b=\frac{13}{21}$$，$$c=\frac{17}{25}$$，则$$a$$、$$b$$、$$c$$的大小顺序是． 
选项为:A:$$a ~\textless{} ~b ~\textless{} ~c$$  B:$$a ~\textgreater{} ~b ~\textgreater{} ~c$$  C:$$b ~\textless{} ~c ~\textless{} ~a$$  D:$$b~ \textgreater~ c ~\textgreater{} ~a$$  请回答其中一个选项.