Company ABC produces tennis balls. One dozen tennis balls sells for $5 and has variable costs of $4.

Company ABC produces tennis balls. One dozen tennis balls sells for $5 and has variable costs of $4. ABC's fixed costs are $30,000 per year. How many dozen tennis balls must ABC sell if it wants to earn a profit that equals 10% of sales revenue?

A. 30,000 dozen

B. 50,000 dozen

C. 60,000 dozen

D. 70,000 dozen