How can a total costs act as a barrier entry

Economies of scale and network externalities are two types of barrier to entry. ... Economies of scale are cost advantages that large firms obtain due to their size. They occur because the cost per unit of output decreases with increasing scale, as fixed costs are spread over more units of output.

Explanation:

b: the establishment clause  

b: socialism  

yes based on alexanders actions he deserved the title of "the great". his empire covered about 3,000 miles and he was able to establish the empire over a 13 year period of time. he was able to conquer many different places. he also defeated the persians. he conquered egypt and developed a city and named it after himself.