Which of the following statements is $($are$)$ true?

A$)$ The mean absolute deviation can be used as a measure of forecast error.

B$)$ Forecast error is RARELY distributed normally about the average demand.

C$)$ In a normal distribution the error will be within plus or minus $3$ MAD of the average about $98\%$ of the time.

D$)$ Forecast error is the difference between forecast supply and actual demand.

E$)$ Both A and $C.$