The acceleration of the system shown in the figure is given by the expression (coefficient of friction between m, and surface is \[\mu \])

• A. \[a=\frac{\left( {{m}_{2}}-\mu {{m}_{1}} \right)}{\left( {{m}_{1}}+{{m}_{2}} \right)}\]
• B. \[a=\frac{{{m}_{1}}g}{\left( {{m}_{1}}+{{m}_{2}} \right)}\]
• C. \[a=\frac{\left( {{m}_{1}}+\mu {{m}_{2}} \right)}{\left( {{m}_{1}}+{{m}_{2}} \right)g}\]
• D.        \[a=\frac{\left( {{m}_{1}}-{{m}_{2}} \right)\mu }{\left( {{m}_{1}}+{{m}_{2}} \right)g}\]