The Random Walk Model Is Written As $Y _ { t } = Y _ { t - 1 } + m + e _ { t }$

Multiple Choice

The random walk model is written as: $Y _ { t } = Y _ { t - 1 } + m + e _ { t }$
) In this model, $e _ { t }$
Represents the:

A) average of the Y's
B) average of the X's
C) forecasted value
D) random series with mean 0 and some constant standard deviation