Answer:
D. $2.30
Step-by-step explanation:
 The computation of the cost per equivalent unit for direct material is shown below:
= Total material cost ÷ Equivalent unit of materials 
where, 
Total material cost is $4,100
And, the equivalent unit of material is 
= Units transferred out + ending work in process units
= 1,600 + 180
= 1,780 
The units transferred out is 
= Beginning units + started units - ending units 
= 290 units + 1,490 units - 180 units 
= 1,600 units 
So, the cost per equivalent for direct material is 
= $4,100 ÷ 1,780 units 
= $2.30