(Automatic control systems) The plot in the following figure shows the unit step response of a first-order system.Transfer function of the system is

2. The plot in the following figure shows the unit step response of a first-order system. Transfer function of the system is 2 1.8 1.6 1.4 1.2 Amplitude 1 0.8 0.6 0.4 0.2 0 0 $ A. TF 1 1+ 5s 2 1+ 3s 10 15 20 Time (seconds) 2 B. TF 1 + 15s 1 D. TF 1+15s C. TF