Ballantyne Uniforms Will Be Purchasing One or Other of Two

Ballantyne Uniforms will be purchasing one or other of two models of high efficiency industrial washing machines. It will also have to purchase an extension of the racking with linen bags that move dirty laundry to the washers. The racking system should be viewed as a

A) Sunk cost
B) Common future cost
C) Opportunity cost
D) Ancillary cost
E) Variable cost