Consider the following process Yt = c + Yt1 + t , t = 1, . . . , T, where t is a white noise error term (i.e. t W N(0, 2 )) and Y0 = 0. REQUIRED: (i) Under what condition is the above process a martingale? Explain your answer. (2 marks) (ii) Compute the expectation and variance of Yt