If $\sin^2 \theta+ \cos^2 \theta = 1$, then what is $\sec \theta$ in terms of $\sin \theta$ ?

Question

$\begin{array}{1 1} (a)\; \large\frac{1}{\sqrt{1-\sin^2\theta}} \\ (b)\; \large\frac{1}{\sqrt{\sin^2 \theta -1}} \\ (c)\; \large\frac{-1}{\sqrt{1-\sin^2 \theta} } \\ (d)\; \large\frac{-1}{\sqrt{\sin^2 \theta -1}} \end{array}$