Which property is true for the Characteristic Function ϕX(t)=E[eitX]\phi_X(t) = E[e^{itX}]ϕX(t)=E[eitX]?
ϕX(0)=1\phi_X(0) = 1ϕX(0)=1
ϕX(0)=0\phi_X(0) = 0ϕX(0)=0
∣ϕX(t)∣>1|\phi_X(t)| > 1∣ϕX(t)∣>1
ϕX(t)\phi_X(t)ϕX(t) is always real