The addition of open loop zero pulls the root loci towards:
(a) The left and therefore system becomes more stable
(b) The right and therefore system becomes unstable
(c) Imaginary axis and therefore system becomes marginally stable
(d) The left and therefore system becomes unstable
The question was posed to me during an interview for a job.
My question is taken from The Root Locus in chapter The Root Locus Technique of Control Systems