Final answer:
The correct answer is b.) Immigration is a federal power as determined by the Constitution, with states having limited influence over related policies. While the Tenth Amendment reserves certain powers for states, immigration regulation is not included and remains under federal jurisdiction.
Step-by-step explanation:
The power to regulate immigration is best described as a federal power. According to the United States Constitution, immigration and naturalization are expressed powers given to the federal government. While states have attempted to influence immigration policies, especially border states like Arizona and Texas, it is important to note that federal immigration laws trump state laws. The Tenth Amendment reserves certain powers exclusively to state governments, and although it allows them to legislate on matters not expressly handled by the federal government, immigration is not one of those areas. States can enact laws impacting areas such as education and welfare benefits to undocumented immigrants, but they cannot usurp the overarching federal authority on immigration matters.