Answer:
The correct answer is letter "D": economies of scale.
Step-by-step explanation:
Economies of scale imply production becomes more productive as the number of products produced increases. In most cases, businesses that reach economies of scale, by increasing production, lower the average cost of their goods. In economies of scale, each product's cost can depend on the size of the industry or the size of an individual firm.
Thus, governments would provide monopoly licenses to trash collectors so they can specialize in their performance by being the only organization in charge of that task in the market.