An operation analyst is forecasting this year's demand for one of his company's products based on the following historical data: (4 year ago Quantity sold was 1051), (3 year ago Quantity sold was 1126), (2 year ago Quantity sold was 1829 ) and the last year Quantity sold was 1914 . The previous trend line had predicted 1200 for three years ago, 1250 for two years ago and 1300 for last year. What was the mean squared error (MSE) for these forecasts? a. 239237.67 b. 422.32999 C. 0.23 d. 23.440001