The value of $x$ satisfying $\sin^{-1}x+\sin^{-1}(1-x)=\cos^{-1}x$ are

Question

$(a)\;0,\large\frac{1}{2}$$\qquad(b)\;1,2\qquad(c)\;0,2\qquad(d)\;None\;of\;these$