explain also

A time series regression equation measuring the number of surfboards sold by a surfboard manufacturing company in Australia is given below: Y = 35 + 4Q1 + 0.5Q: + 8Q4 + 3t with t in quarters and the first observation of the dataset is December 2015 and Q 1 is the indicator variable for March, Q: is the indicator variable for September and Q 4 is the indicator variable for December. Which of the following statements is correct? O There is a mistake with this regression model because all the coefficients of the indicator variables are positive. O There is no indicator variable for the June quarter in this model because there is no seasonal effect in June due to winter in Australia. O There is a mistake with this model because the indicator variable for the June quarter has been left out. O There is no indicator variable for the June quarter because the model has an intercept and including the June quarter would result in perfect multicollinearity