Starling, Inc. uses the sum-of-the-years'-digits method. On January 1, 2018, Starling purchased a new machine for $210,000. The new machine has an estimated useful life of nine years and the salvage value was estimated to be $7,500. Depreciation was computed using the sum-of-the-years'-digits method. What is the book value of the machine on the December 31, 2019 balance sheet?

A. $124,425

B. $133,500

C. $169,500

D. $130,666