Acost that stays constant is
a. a.
variable cost
c. marginal cost
b. fixed cost
d. total cost

b. fixed cost

Explanation:

Cost theory describes that there are three main types of cost, fixed cost, variable cost, and total cost. Fixed costs are those costs that are recurring every month, usually of the same value and that cannot be changed in the short term, such as renting a place where a factory is installed. Variable costs are all costs that vary over time and that may change over the short term. For example, in a factory, variable costs are labor and inputs used in production. Finally, the total cost is simply the sum of fixed costs and variable costs.