Let a circle C in complex plane pass through the points $${z_1} = 3 + 4i$$, $${z_2} = 4 + 3i$$ and $${z_3} = 5i$$. If $$z( \ne {z_1})$$ is a point on C such that the line through z and z₁ is perpendicular to the line through z₂ and z₃, then $$arg(z)$$ is equal to :

Let $$A = \{ z \in C:1 \le |z - (1 + i)| \le 2\} $$

and $$B = \{ z \in A:|z - (1 - i)| = 1\} $$. Then, B :