Answer:
D. ​$166
Explanation:
The computation of the unit product cost is shown below:
=  Direct material per unit + direct labor per unit + Variable manufacturing overhead per unit + Fixed manufacturing overhead ​ per unit
= $45 per unit + $20 per unit + $65 per unit + $35.71 per unit
= 165.71
The fixed manufacturing overhead per unit is computed by
= Fixed manufacturing overhead ​cost ÷ number of units produced
= $500,000 ÷ 14,000 units
= $35.71