Martin Company incurred the following costs for 70,000 units: variable costs $420,000; fixed costs $392,000; Martin has received a special order from a foreign company for 3,000 units. There is sufficient capacity to fill the order without jeopardizing regular sales. Filling the order will require spending an additional $6,300 for shipping. If Martin wants to break even on the order, what should the unit sales price be?

a. $6.00

b. $8.10

c. $11.60

d. $13.70

How do I solve this?

Thank you