Answer:
A. Legal positivism
Step-by-step explanation:
Legal positivism is a school of thought that was developed in the early 18th century and focuses in the fact that rules become laws and that they create obligations that are legal and that people are supposed to comply with. In other words, a law is a rule that comes from people who have certain authority and that the society accepts.
In this example, Thoreau refused to pay his taxes when the States declared war on Mexico, his neighbor agreed that war was unjust buy paid his taxes because the law required him to pay the tax. In this case, the neighbor is taking a rule as a law (even though he considers it unfair) because someone with authority said so. Thus, this would be an example of Legal Positivism.