If $ \sin ^{-1} \bigg( \large\frac{x}{5}\bigg) $$ + cosec^{-1} \bigg( \large\frac{5}{4}\bigg)=\frac{\pi}{2}$, then x is

Question

$\begin{array}{1 1} 3 \\ 4 \\ 5 \\ 1 \end{array} $