Which legal amendment allowed states to regulate the insurance industry?

The Tenth Amendment is the correct answer because it grants states the power to legislate on issues that are not specifically reserved for the federal government. This includes the authority to regulate industries such as insurance. The founding principles of federalism in the United States allocate certain responsibilities and powers to states, and the regulation of insurance is one of those areas where states have the authority to create their own laws and guidelines.

In particular, the insurance industry has historically been regulated at the state level, allowing each state to tailor its insurance laws to meet the needs of its residents. This state-level control promotes local oversight and flexibility in addressing issues that may vary significantly from one state to another.

The other amendments listed do not pertain specifically to the regulation of insurance. The First Amendment focuses on freedom of speech and religion, the Fifteenth Amendment addresses voting rights, and the Second Amendment deals with the right to bear arms. Each of these amendments serves important functions in American law but does not involve the powers granted to states regarding the regulation of industries like insurance.