On January 3, 2013, Munoz Co. purchased machinery. The machinery has an estimated useful life of eight years and an estimated residual value of $30,000. The depreciation applicable to this machinery was $65,000 for 2015, computed by the sum-of-the-years'-digits method. The acquisition cost of the machinery was Select one: a. $360,000. b. $420,000. c. $468,000. d. $390,000