The correct option is C C(s)R(s)=K(s+1)(s+2)−K
This is converse of root locus(called complementary root locus) having no zero.
As, its G(s)H(s)=K(s+1)(s+2)
Its converse root locus only valid when K < 0
So,C.L.T.F.=G(s)H(s)1−G(s)H(s)
=K(s+1)(s+2)1−K(s+1)(s+2)=K(s+1)(s+2)−K