Economies of scale occur when a firm'sa. marginal costs are constant as output increases. b. long-run average total costs are decreasing as output increases. c. long-run average total costs are increasing as output increases. d. marginal costs are equal to average total costs for all levels of output.

Option (b) is correct.

Explanation:

Economics of scale occurs when a firm's long run average total costs decreases as there are more number of units produced.

Basically, economics of scale is a cost advantage that is experienced by the firms or companies by increasing the level of production.

This is happened because of the indirect relationship between the per unit fixed cost and output level. The larger the output produced results in lower per unit fixed cost.

There are two types of economies of scale that are internal and external economies of scale.

answer; (a) searching for information can be done quickly;

the answer would be voluntary exchange -

"the act of buyers and sellers freely and willingly engaging in market transactions. moreover, transactions are made in such a way that both the buyer and the seller are better off after the exchange than before it occurred."

hope this : )

-shy