Violet Flowers expects to sell 3,000 plants a month. She estimated the following monthly costs: Variable Costs $ 7,500 Fixed Costs $15.000 In her first month of operations, Violet sold 3,000 plants for $24,000. In the second month, Violet increased advertising by $1,800, which increased total sales to $28,000. What is her margin of safety? OA) 10% B) 12% C) 18% D) 22%