If the chord $y=mx+1$ of the circle $x^2+y^2=1$ substance on angle of measures $45^{\circ}$ at the major segment of the circle then value of m is

Question

$\begin{array}{1 1}(A)\;2 \pm \sqrt 2 \\(B)\;-2 \pm \sqrt 2 \\(C)\;-1 \pm \sqrt 2 \\(D)\;none\;of\;these \end{array}$