Which amendment grants individual states the authority to enact laws and establish their law enforcement systems?

The correct answer focuses on the 10th Amendment, which is essential in defining the division of powers between the federal government and individual states. The 10th Amendment states that powers not delegated to the federal government by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people. This constitutional provision empowers states to enact their own laws and establish their law enforcement systems, allowing them to address local issues and govern according to the needs of their communities.

In the context of law enforcement, this means that each state can create laws, regulations, and agencies tailored to its specific circumstances, promoting flexibility and responsiveness to local governance.