Answer:
(C) decreases in long-run average costs resulting from increases in output.
Step-by-step explanation:
Economies of scale are those where the larger the scale of operation of a company is (increases in output), the smaller the cost per unit of output is (decreases in average costs). This concept applies to a great variety of companies, and it was first developed by Adam Smith. It is also the opposite of disectomies of scale.