The true set of values of '\( K\)' for which \( {sin}^{-1}\left(\frac{1}{1+{sin}^{2}x}\right)=\frac{K\pi }{6}\) may have a solution is
(a) \( \left[\frac{1}{4},\frac{1}{2}\right]\)
(b) \( [1,3]\)
(c) \( \left[\frac{1}{6},\frac{1}{2}\right]\)
(d) \( [2,4]\)