The correct option is A Vo(s)Vi(s)=ss2+3s+1
After taking Laplace transform, the series combination of R1 and C1 gives:
R1+1sC1
Similarly, the parallel combination of R2 and C2 gives:
R2sC2R2+1sC2
Substituting, R1=R2=C1=C2=1 makes the above combinations 1+1/s and 1/s1+1/s
On applying the voltage divider rule, we get
Vo(s)=1/s1+1/s1+1s+1/s1+1/sVi(s)
Vo(s)Vi(s)=1s+1s(s+1)+(s+1)+ss(s+1)
Vo(s)Vi(s)=ss2+3s+1