The open loop transfer function of a unity feedback system is given by \(\frac{\mathrm{K}}{s(s+1)}\). If the value of gain \(\mathrm{K}\) is such that the system is critically damped, the closed loop poles of the system will lie at:
(a) -0.5 and -0.5
(b) \(\pm j 0.5\)
(c) 0 and -1
(d) \(0.5 \pm j 0.5\)