Exhibit 6-6 Sauer Company Sells Folding Chairs for $40.00 Per Unit.Variable Cost

Exhibit 6-6
Sauer Company sells folding chairs for $40.00 per unit.Variable cost is $15.00 per unit.Each chair requires 4 direct labor hours and 2 machine hours to produce.
-Refer to Exhibit 6-6.Which of the following is the correct contribution margin per unit?

A) $15.00
B) $5.00
C) $40.00
D) $25.00
E) None of the answer choices is correct.