Which of the following statements about the initialization of the Holt-Winter Model is true?

Select all correct answers

Linear regression is the only known method for initialization.

The training set must be of the same size as the initialization set.

If there is seasonality, the initialization set should cover at least 2 periods of the seasonal trend.

If there is seasonality, the seasonality indexes have to be estimated and normalized. a^0 and b^0 can be estimated using linear regression.

None of the above.