If you can explain your answer(s), I would really appreciate it! thanks

4. . Randy's Pizza delivers pizzas to dormitories and apartments near a major state university. The company's annual fixed costs are $48,000. The sales price averages $9, and it costs the firm $3 to make and deliver each pizza. Required: A. How many pizzas must Randy's sell to break even? B. How many pizzas must the company sell to earn a target profit of $54,000? C. If budgeted sales total 9,900 pizzas, how much is the company's safety margin in dollars? D. Tony's assistant manager, an accounting major, has suggested that the firm should try to increase the contribution margin per pizza. Explain the meaning of "contribution margin" in layman's terms