Adam was a professional classical guitar player undil his motorcycle accident that left him disabled, After long months of thorapy, he hired an experienced uthier(maker of stringed instruments) and started a small shop to make and sell Spanish guitars. The guitars sell for $900 and the fixed monthly operating costs are as follows: Rent and utilities Wages and benefits to luthier Other expenses $800 3,000 500 Adam's accountant told him about contribution margin ratios and he understood clearly that for every dollar of sales, $0.60 went to cover his foxed costs, and that anything past that point was pure profit How many guitars does Adam have to sell each month to break even? (Round your final answer up to the nearest whole unit.) O A. 5 guitars O B. 6 guitars O C. 7 guitars O D. 8 guitars