Explain the rule of marginal
utility and how it works in real life.

In economics, the law of diminishing marginal utility states that the marginal utility of a good or service declines as its available supply increases. Economic actors devote each successive unit of the good or service towards less and less valued ends.

Explanation:

the correct answer is "c: merchants" and "e. soldiers".

the song dynasty was known as the first government in the world to introduce paper currency. it was also the first chinese government which established a permanent standing navy. finally, the first compass was introduced during this period of government.

all of these innovations heavily affected commerce in a positive way. printed money dynamize commerce within the borders of the empire due to an easier way to quantify value during the trade. the introduction of the compass trade routes to be faster. finally, the introduction of a standing navy regulate trade routes.

regarding military affairs, gunpowder was created during this period. this was a tremendous improvement that was widely utilized by the military in order to innovate in the manufacturing of weapons.