help me please!!

Pisces Company manufactures sonars for fishing boats. Model 100 sells for $400. Pisces produces and sells 6,000 units per year. Cost data are as follows: An offer has come in for a one - time sale of 300 units at a special price of $120 per unit. The marketing manager says that the sale will not affect the company's regular sales activities, and that it will not require any variable selling and administrative costs. The production manager says that there is plenty of excess capacity and the sale will not impact fixed costs in any way. What is the effect of this deal on operating income? B. Operating income decreases by $7,500. C. Operating income increases by $7,500. D. Operating income increases by $400