Consider the following process: Which of the below models is a correct first-order-plus-time-delay approximation for this process? a. Gappros(s)=0.172e(2.5s)/(0.2s+1) b. Gapprox(s)=4e(1.8s)/(2.5s+1) c. Gapprox(s)=8e(2.94)/(6s+1) d. Gapprou(s)=0.25e(0.2s)/((0.2s+1)(0.04s+1)(0.008s+1))