At a monthly volume of $50,000, a company incurs variable cost of $20,000 and fixed costs of $12,000. Required: Select and Copy the following question parts (A, B, and C) into the text box below and answer the question parts: (show your work to be considered for partial credit) Determine each of the following values: A. Contribution margin ratio B. Monthly break-even sales volume: C. Monthly margin of safety in dollars