A steel wire of 8m in length is stretched by 1mm of cross sectional area $2mmm^2$ .If young modulus of steel is $2\times 10^{11}N/m^2$.What is elastic potential energy?

Question

$\begin{array}{1 1}(A)\;.025J\\(B)\;.25J\\(C)\;.035J\\(D)\;0.045J\end{array} $