To improve productivity, a local bakery rents a machine that mixes, partitions, and then bakes dough for a variety of pastries. The machine costs the business $2, 500 per month to rent and operate, regardless of output. The cost of renting the machine is classified as _. (1 point)

A.• marginal cost
B.O a variable cost
C.O a fixed cost
D.• marginal revenue