Let S be the set of all complex numbers z satisfying | z- 2 + i | ≥√5. If the complex number z0 is such that 1/| z0 -1| is the maximum of the set {1/ | z- 1|:z ∈ S } then the principal argument of 4- z0 - z0 / z0 -z0 +2i is
(A) π/2
(B) π/4
(C) -π/2
(D) 3π/4