$\int_{0}^{1} \frac{\cot ^{-1} x d x}{1+x^{2}}$ এর মান কত ?

$\frac{\pi^{2}}{64}$

$\frac{\pi^{2}}{32}$

$\frac{\pi^{2}}{16}$

$\frac{3 \pi^{2}}{32}$