87. Baker Corporation has provided the following production and average cost data for two levels of monthly production volume. The company produces a single product. Production volume ................. 1.000 units 3,000 units Direct materials ...................... $30.90 per unit $30.90 per unit Direct labor ............................ $40.20 per unit $40.20 per unit Manufacturing overhead ......... $64.60 per unit $33.80 per unit The best estimate of the total variable manufacturing cost per unit is: A. $89.50 B. $18.40 C. $71.10 D. $30.90