Ifxisan exponential distribution with parameter , verify the following formula.Use two steps of integration by parts to show that Var(x)=12.You will use the following terms to verify the variance using integration by parts.First integration by parts:(1),([u1=x2,,dv1=e-xdx,],[du1=dx,,v1=e-xdx=-e-x])Second integration by parts:(2),([u2,=2x,,dv2=e-xdx,],[,du2=2dx,,v2=e-xdx=-1e-x])Below are the steps, but placed in a random order.A.0x2e-xdx-(1)2=B.E[x2]-(E[x]]C.by(1)[-x2e-x]0-0(-2xe-x)dx-12=D.22-12=E.by(2)[-2xe-x]0-0(-2e-x)dx-12=F.12