Concept:The word “axiom” means a basic rule or principle that is widely accepted as true without proof.
Explanation:An axiom is a statement that is considered self-evidently true and is used as a foundation for further reasoning.
It is not about similarity or equality, so option A does not fit.
It is not about how people should behave, so option C does not fit.
Although axioms are used in mathematics, they are not limited only to the idea of exact equality, so option D is too narrow.
The best meaning is a rule or principle that most people believe to be true, which matches option B.
Answer:B. Rule or principle that most people believe to be true