Knicks'N'Knacks produced 15,000 units in June at a cost of $39,250 In July, they produced 14,000 units

Question:

Knicks'N'Knacks produced 15,000 units in June at a cost of $39,250 In July, they produced 14,000 units at a cost of $37,500 In August, they produced 14,200 units at a cost of $36,500
What is the company's fixed cost?
a) $13,000
b) $12,350
c) $12,348
d) $11,650