Four different models were fit to the same time series. The first 100 time periods were used for the training period and the last 12 periods were treated as a validation period. Assume that the models make sense practically and fit the data reasonably well. Below are the RMSE values for each of the models: Model A, Training Period RMSE = 543 Model A, Validation Period RMSE = 690 Model B, Training Period RMSE = 669 Model B, Validation Period RMSE = 675 Model C, Training Period RMSE = 670 Model C, Validation Period RMSE = 650 Model D, Training Period RMSE = 437 Model D, Validation Period RMSE = 375 Which model appears more useful for retrospectively describing the different components of this time series? O Model A O Model B O Model C O Model D