Consider the following two subsets of $\mathbb { C }$ :
$$A = \left\{ \frac { 1 } { z } : | z | = 2 \right\} \text { and } B = \left\{ \frac { 1 } { z } : | z - 1 | = 2 \right\} .$$
Then\\
(A) $A$ is a circle, but $B$ is not a circle.\\
(B) $B$ is a circle, but $A$ is not a circle.\\
(C) $A$ and $B$ are both circles.\\
(D) Neither $A$ nor $B$ is a circle.