An AR(2)process Is Written as
A) $\varepsilon _ { t } = \rho \varepsilon _ { t - 1 } + u _ { t }$

Multiple Choice

An AR(2) process is written as

A) $\varepsilon _ { t } = \rho \varepsilon _ { t - 1 } + u _ { t }$
B) $\varepsilon _ { i } = \rho \varepsilon _ { i - 1 } + u _ { i }$
C) $\varepsilon _ { t } = \rho _ { 1 } \varepsilon _ { t - 1 } + \rho _ { 2 } \varepsilon _ { t - 2 } + u _ { t }$
D) $\varepsilon _ { i } = \rho _ { 1 } \varepsilon _ { i - 1 } + \rho _ { 2 } \varepsilon _ { i - 2 } + u _ { i } .$