Which one of the following statements about the patterns of a demand series is false?

Question $8$ Select one:

A$.$

Every demand series has at least a random component.

B$.$

The trend, over an extended period of time, always increases the average level of the series.

C$.$

Estimating cyclical movement is difficult. Forecasters do not know the duration of the cycle because they cannot predict the events that cause it$.$

D$.$

The five basic patterns of most business demand series are the horizontal, trend, seasonal, cyclical, and random patterns.