设$$a\textgreater0\textgreater b\textgreater c$$，$$a+b+c=1$$，$$M=\frac{b+c}{a}$$，$$N=\frac{a+c}{b}$$，$$P=\frac{a+b}{c}$$，则$$M$$，$$N$$，$$P$$之间的大小关系是．
选项为:A:$$M\textgreater N\textgreater P$$  B:$$N\textgreater P\textgreater M$$  C:$$P\textgreater M\textgreater N$$  D:$$M\textgreater P\textgreater N$$  请回答其中一个选项.