The constant c has an important effect on the long-term forecasts obtained from the models:

.

Which statement about this effect is not correct (multiple choice):

a.If c=0 and d=2, the long-term forecasts will follow a quadratic trend.

b.If c=0 and d=0, the long-term forecasts will go to zero.

c.If c0 and d=0the long-term forecasts will go to the mean of the data.

d.If c0 and d=2, the long-term forecasts will follow a quadratic trend.