Armand has opted to sell his famous funnel cakes at the local farmer's market instead of opening his own store. After his first month, he summarized the following financial data: unit variable cost per funnel cake was $2 and the monthly rental fee for the space at the market which includes electricity is $700. Armand initially decided to set the selling price per unit for each funnel cake at $4. If the sales for the first month were 500 funnel cakes, what was Armand's margin of safety in units? 650 units 500 units 350 units 150 units