Answer:
B. $24,000.
Explanation:
The computation of the depreciation per units under the units-of-production method is shown below:
= (Original cost - residual value) ÷ (estimated production units)
= ($180,000 - $20,000) ÷ (40,000 units)
= ($160,000) ÷ (40,000 units)
= $4 per unit
Now for the second year, it would be
= Production units in second year × depreciation per unit
= 6,000 units × $4
= $24,000