Two engineers are analyzing step-test data from a bioreactor. Engineer A says that the data indicate a second-order over damped process, with time constants of 2 and 6 min but no time delay. Engineer B insists that the best fit is a FOPTD model, with τ = 7 min and θ = 1 min. Both engineers claim a proportional controller can be set at a large value for K_c to control the process and that stability is no problem. Based on their models, who is right, who is wrong, and why? Use a frequency response argument.