$\begin{array}{1 1}(A)\;\large\frac{\sqrt 3+1}{2\sqrt 2}\\(B)\;\large\frac{\sqrt 3-1}{2\sqrt 2}\\(C)\;\large\frac{\sqrt 2+1}{2\sqrt 2}\\(D)\;\large\frac{\sqrt 2-1}{2\sqrt 2}\end{array} $
