An increase in a firm's scale of production leads to no change in average total cost as long as there are

A) economies of scale.
B) diseconomies of scale.
C) negative returns to scale.
D) constant returns to scale.

Constant Returns to Scale

A situation in production where increasing all inputs by a certain factor results in output increasing by the same factor.

Average Total Cost

The total cost divided by the quantity of output produced; it includes all variable and fixed costs.