$9\mathrm{.}4$ For the following OLTF, select the forward path compensator that will shift the vertical branches of the root locus to the left. OLTF$=10$K$/(($s$+1)($s$+2)).$ a$)(0\mathrm{.}1($s$+30))/($s$+3),$ b$)(0\mathrm{.}5($s$+1))/($s$+0\mathrm{.}5),$ c$)(10($s$+3))/($s$+30),$ d$)(4($s$+2))/($s$+0\mathrm{.}5)$