Evaluate the following $\displaystyle\int\frac{dx}{x\sqrt{x^4-1}}\;(Hint:Put\;x^2=\sec\theta)$

Question

$\begin{array}{1 1} (A)\;\sec ^{-1} (x^2)+c \\ (B)\;\frac{1}{4} [\sec ^{-1} (x^2)]+c \\ (C)\;\frac{1}{6} [\sec ^{-1} (x^2)]+c \\ (D)\;\frac{1}{2} [\sec ^{-1} (x^2)]+c\end{array}$