Work done $= \large\frac{1}{2} $$ \times$ Young's module $ \times$ strain $^2$ $ \times$Volume
$W=\large\frac{1}{2}$$ \times Y \times \large \frac{\Delta l^2}{L^2} \times$$ AL$
$\qquad= \large\frac{Y A \Delta L^2}{2L}$
$\qquad= \large\frac{2 \times 10^{11} \times 10^{-6} \times 10^{-6}}{2 \times 1}$
$\qquad=0.1\;J$
Hence d is the correct answer.