On January 3, 2016, Rainbow Co. purchased machinery. The machinery has an estimated useful life of eight years and an estimated salvage value of $60,000. The depreciation applicable to this machinery was $130,000 for 2018, computed by the sum-of-the-years'-digits method. The acquisition cost of the machinery was

A) $720,000

B)$780,000

C)$840,000

D)$936,000

Please show how you worked it out. Thank you.