Let x be the annual growth rate of the money supply and y be the unemployment rate in year t. Both y and x are stationary, and are modelled as a vector autoregression, VAR(1). With the VAR(1) model, in general, there O a. are two equations both with ()t.1, Xt.1) on the right-hand-side. O b. is one equation with ()t-1. xt-1) on the right-hand-side. O c. are two equations both with x on the right-hand-side. O d. is one equation with x_; on the right-hand-side