A system with characteristic equation $$s^2 + 2 s^3 + 11 s^2 + 18 s + 18 = 0$$ will have closed loop poles such that

A

All poles lie in the left half of the s-plane

B

All poles lie in the right half of the s-plane

C

Two poles lie symmetrically on the imaginary axis of the s-plane.

D

No pole lies on the imaginary axis of the s-plane.