If \( z_1 \) and \( z_2 \) are two distinct complex number such that \( \left|\dfrac{z_1-2z_2}{\dfrac{1}{2}-{z_1}\bar z_2}\right|=2 \), then
Both \( z_1 \) and \( z_2 \) lie on the same circle
Either \( z_1 \) lies on a circle of radius \( \dfrac{1}{2} \) or \( z_2 \) lies on a circle of radius \( 1 \).
Either \( z_1 \) lies on a circle of radius \( 1 \) or \( z_2 \) lies on a circle of radius \( \dfrac{1}{2} \).
\( z_1 \) lies on a circle of radius \( \dfrac{1}{2} \) and \( z_2 \) lies on a circle of radius \( 1 \).