If \[{{\left( \frac{5}{9} \right)}^{4}}\times {{\left( \frac{5}{9} \right)}^{-10}}={{\left( \frac{5}{9} \right)}^{-4}}{{\left( \frac{5}{9} \right)}^{2a-1}},\]then the value of a is _____.

• A.  1                                
• B.  \[\frac{-5}{2}\]                     
• C.  \[\frac{-5}{4}\]                     
• D.         \[\frac{-1}{2}\]