Answer: D. specialization and division of labor
Step-by-step explanation:
Economies of scale refers to the cost advantages that are reaped by companies when there is efficient production such that production increases and there's lowering of costs.
Economies of scale can be achieved by marketing channels through specialization and division of labor. This can be done by aiding the producers who doesn't have the finance and lacks motivation, or the expertise to market directly to the consumers.