If \[{{(25)}^{7.5}}\times {{(5)}^{2.5}}\div {{(125)}^{1.5}}={{5}^{x}},\] find 'x'.

• A.  \[8.5\]                                 
• B.  \[13\]                  
• C.  \[16\]                  
• D.         \[17.5\]