Mell Co. manufactured 100 personal computers at a cost of $30,000. It can sell them as is for $ 65,000, or install hard disk in them for $25,000 and sell them for $105,000 original manufacturing cost is:

a) An out of pocket cost because it has already been paid.

b) A sunk cost because it is not relevant to the decision.

c) An incremental cost because it is relevant to the decision.

d) A fixed cost because it will the same no matter which action is taken.