Suppose you have the following regression equation where SALES = 100s of cars sold per month, PRICE = average actual price paid by customer for car purchases in month, ADV = monthly advertising expenses, SEPT = dummy variable with value 1 for Sept and 0 for all other months; and FEB = dummy variable with value of 1 for February and 0 for all other months: Sales = ß0 + ß1Price + ß2Adv + ß3Sept + ß4Feb. If ß3 = 3.5 and is significantly different from zero, this result indicates that
A) sales are higher in September than in all other months.
B) sales in September are higher than sales in all other months excluding February.