A complex number \(z\) is said to be unimodular, if \(|z|\neq 1\). If \(z_{1}\) and \(z_{2}\) are complex numbers such that \(\frac {z_{1}-2z_{2}}{2-z_{1}\bar z_{2}}\) is unimodular and \(z_{2}\) is not unimodular. Then, the point \(z_{1}\) lies on a( )
A. straight line parallel to \(X\)-axis
B. straight line parallel to \(Y\)-axis
C. circle of radius \(2\)
D. circle of radius \(\sqrt {2}\)