ABC Company had an old machine with an original cost of $84,000 and an estimated disposal value of 0. ABC company was considering the purchase of a new machine having a five year life, costing $120,000, and having an estimated disposal value of $20,000 at the end of five years. in it's decision concerning the possible purchase of the new machine, how should ABC Company consider the original cost of the old machine?

A. As a relevant cost of $84,000

B.As a new cash outflow of $84,000

C.As a sunk cost of $84,000

D.As a differential cost of 84,000

E.None of the above