Question 6. For the quarterly time series, how many statements are correct? 0 1 2 3 Quarter Demand Data 1 2 3 4 5 6 7 8 9 160 140 130 170 160 140 130 170 160 (A) Using a nave forecast method, the MAD for the forecast for quarter 10 is 20 (B) Using a moving average forecast method with an interval of 4, the MAD for the forecast for quarter 10 is 14 (C) Using an exponential forecast method with an alpha of 0.47 and a forecast for quarter 1 of 140, the MAD for the forecast for quarter 10 is approximately 17