$\mathrm {\dfrac{d}{d x}\left\{\tan ^{-1}\left(e^{x}\right)\right\}=}$ কত?

$\mathrm { \dfrac{e^{x}}{1+e^{x^{2}}}}$

$\dfrac{1}{1+\mathrm{e}^{\mathrm{x}}}$

$\mathrm { \dfrac{e^{x}}{1+e^{2 x}}}$

$\mathrm { \dfrac{1}{1+e^{x^{2}}}}$