Answer:
A. A loss of $38,000
Step-by-step explanation:
Total depreciation on the tractor = (180,000 - 20,000) * (2,400 + 2,100) / 10,000 = $72,000
Net book value on January 1, 2018 = 180,000 - 72,000 = $108,000
Loss on sale = 70,000 - 108,000 = $38,000