Suppose That the Total Fixed Cost for a Guitar Manufacturer

Suppose that the total fixed cost for a guitar manufacturer is $90.The marginal cost of the first guitar produced is $80 and decreases by $10 for the next three guitars produced.Thereafter,the marginal cost increases by $10 for each successive guitar.
-Refer to the information above to answer this question.What is the manufacturer's break-even price?

A) 0.
B) $64.
C) $80.
D) $82.
E) $90.