A unity feedback system with the open loop transfer function \(\mathrm{G}(s)=\frac{1}{s(s+2)(s+4)}\) has gain margin of
(a) \(33.6 \mathrm{~dB}\)
(b) \(32.4 \mathrm{~dB}\)
(c) \(32.6 \mathrm{~dB}\)
(d) \(30.6 \mathrm{~dB}\)