Given that Z is a zero-mean white noise process with variance σ2, which of the following are I(O) processes?
(A) Xt = Xt-1 + Zt
(B) Xt = αXt-1 + Zt where 0 < α <1
(C) Xt = Zt + Zt-1
(D) Xt = 8 + Xt-1 + Zt
Choose the correct answer from the options given below:
1
(C) Only
2
(B) Only
3
(B) and (C) Only
4
(B), (C) and (D) Only