Legalism is a philosophical current that was born in China during the warring states era, between 475 and 221 BCE. Initially proclaimed by philosophers like Shang Yang, Li Si and Hanfeizi, this philosophy became the framework under which the Qin dynasty worked and led the first of all the Chinese empires.
Before 475, China was divided into smaller feudal territories and one such territories was governed by the Qin. The Qin, were steadfast legalists who believed strongly in the incapacity of people to rule themselves and to control themselves. Which is why they advocated and practiced the setting of rigid rules, educational campaigns to force the people to believe what they believed and a system of punishment and awarding that came into effect depending on the behavior of people. The Qin, though a strong and the first Chinese empire, did not last very long precisely because of its stringent and almost brutal principles. Another thing legalists, and especially the Qin, believed, was that the power of a ruler did not come from the election of the people, but through divine selection, which made the emperor unaccountable to anyone for his decisions and freed him from any kind of control by the people.
Finally, because the Qin strongly believed in rules and thought that rules and their upholding justified any means, they used the Mandate of Heaven to impose their ruling on the newly conquered territories and justified their power under this Mandate that people believed was sent by the gods. This is why, the correct answer would be D.
