Martin's accountant told him about contribution margin ratios, and Martin understood clearly that for every dollar of sales, $0.60 went to cover his fixed costs, and anything above that point was profit. Martin wishes to earn $3,000 of operating profit each month. Calculate the number of guitars Martin will need to sell to achieve the target profit. (Round your answer up to the nearest whole guitar.) A. 4 guitars B. 3 guitars C. 12 guitars D. 13 guitars