Let $z$ be a non-zero complex number such that $\frac { z } { 1 + z }$ is purely imaginary. Then (A) $z$ is neither real nor purely imaginary (B) $z$ is real (C) $z$ is purely imaginary (D) none of the above
(A) Check (B) and (C) are false, and then that (A) is true.
Let $z$ be a non-zero complex number such that $\frac { z } { 1 + z }$ is purely imaginary. Then\\
(A) $z$ is neither real nor purely imaginary\\
(B) $z$ is real\\
(C) $z$ is purely imaginary\\
(D) none of the above