A steel rod of r=30mm and length 3m.A 50 KN force is applied along its length.Calculate the change in length is $Y=2\times 10^{11}N/m^2$

Question

$\begin{array}{1 1}(A)\;0.52mm\\(B)\;0.23mm\\(C)\;0.26mm\\(D)\;0.50mm\end{array}$