Integrate: $\int \large\frac{e^{-\tan ^{-1}(a^x)}}{[1+(a^x)^2]}$$a^x.dx$

Question

\[\begin {array} {1 1} (a)\;\frac{1}{\log a}.e^{\tan ^{-1}(a^x)}+c \\ (b)\;e^{\tan ^{-1}(a^x)}+c \\ (c)\;\log a.e^{\tan ^{-1}(a^x)}+c \\ (d)\;None \end {array}\]