4.(24%) This problem considers six transfer functions G1 = 1/(s+1), G2 = 2/(s+2), G3 = 1/(s2+s+1),G4= 3(s2+s+3), G5 =2/(s2+3s+2), and G6 = (s+10)((s2+s+10). Their step responses (AI, A2 , A6)are amplitude spectra (B1, B2 , B6) are given in the figures shown in the following pages. Pleasepair each of the transfer functions to one of the step responses and one of the amplitude spectra.(Thatis, if you think A1 is the step response of G1 and B1 is the amplitude spectrum of GI, write youranswer for G1 as G1-A1-B1. Please present your answers in this way for all the six transfer functionsconsidered in this problem.