Calculate the forecasts for periods 12-15 by using a two-period weighted moving average model (enter your responses rounded to the nearest whole number).
a) 12: 417, 13: 417, 14: 417, 15: 417
b) 12: 422, 13: 417, 14: 422, 15: 417
c) 12: 417, 13: 422, 14: 417, 15: 422
d) 12: 422, 13: 422, 14: 417, 15: 417