Answer: Option (C) is correct.
Step-by-step explanation:
Economics of scale is defined as the cost advantages that a country is achieving by increasing their production and lowers their per unit cost.
This is due to the spread of costs over a large number of products which results in lower per unit cost.
Most of the large companies able to produce more by distributing their cost over a large number of goods.
Specialization also give rise to lower per unit cost because specialization of factors of production boosts the production volume of a company and lower per unit cost of production also results from the bulk orders received from the customers, means trade increases.