A system has two real poles and one real zero where $p_1<z_1<\rho_2<0$.
(a) a branch of the root locus lies on the real axis between $z_1$ and $p_2$
(b) a branch of the root locus lies on the real axis between $z_1$ and $p_1$
(c) a branch of the root locus lies on the real axis between $p_2$ and $\infty$
(d) has no branch on the real axis