Lakeside Co. recently determined that one of its processing machines has become obsolete three years early and, unexpectedly, has no salvage value. Which of the following statements is most consistent with this discovery （）

A. Historically, economic depreciation was understated.  

B. Lakeside Co. will owe back taxes.  

C. Historically, economic depreciation was overstated.

因为马克思主义具有与时俱进的理论品质，所以我们要以科学的态度对待马克思主义。