PLEASE ANSWER ASAP

Golden State Petroleum Company is running a coupon promotion to popularize its motor oil. They forecast to sell 66,000 cases of which 60% are expected to be coupon sales. When the 60% is broken down further, 80% of that is expected to be new sales. Assuming that each coupon and non-coupon transaction results in a positive $C and knowing what you do about the relevant issue here, which of the following part(s) of the breakup of the forecast sales is the main source of adverse profit impact for GSPC?

31,680 cases

39,600 cases

26,400 cases

66,000 cases

7,920 cases