Artisan Works is owned and operated by a craftsman who makes replicas of historic firearms for museums, sportsmen, and collectors. The data are as follows: Sales price per unit Variable cost per unit Fixed costs per month $720 500 6,820 If Artisan expects to sell 40 units per month, what is his margin of safety expressed in units per month? O A. 7 units OB. 9 units OC. 40 units OD. 71 units