A closed loop system contains a transfer function G(S) = 1/2(s+1)³ controlled by a constant forward gain K with unit feedback H(s) = I. For this system, the transfer function of the closed loop system is ________.
1) 1/2(s+1)³
2) 2(s+1)³
3) 1/8(s+1)³
4) 8(s+1)³