If A(z1), B(z2) and C(z3) are three points in the argand plane where
| z1 + z2 | = | |z1| - |z2| | and | (1 - i)z1 + iz3 | = | z1 | + | z3 - z1 | ,
where i = √( -1) then
(a) A, B and C lie on a fixed circle with centre (z2 + z3)/2
(b) A, B and C are collinear points
(c) ABC form an equilateral triangle
(d) ABC form an obtuse angle triangle