Based on the text, Aristotle highlights the importance of the state and the fulfillment of contracts, suggesting a reliance on a principle that underpins the functioning of democracy. The most appropriate answer representing that is:
B. The rule of law
This principle emphasizes that laws must govern a nation, as opposed to being governed by the arbitrary decisions of individual rulers, which aligns with Aristotle's mention of the contracts and rights being tied to the state rather than a tyrant.