Fixed cost is a cost:

The correct answer is C. Which do not change in total during a given period despite changes in output.

Fixed costs are costs that do not change in total regardless of the level of output. They are typically costs that are incurred in the short run, such as rent, insurance, and depreciation. Fixed costs are important because they can help businesses to predict their costs and to make decisions about production.

Option A is incorrect because fixed costs do not change in total with changes in output. Option B is incorrect because fixed costs are not partly fixed and partly variable. Option D is incorrect because fixed costs do not remain the same for each unit of output.