Final answer:
The false statement is that the United States has a national police force; it actually has multiple federal law enforcement agencies like the FBI and DHS.
Step-by-step explanation:
The United States does not have a unified national police force. Instead, it has a series of federal law enforcement agencies with specific mandates, such as the Federal Bureau of Investigations (FBI) and the Department of Homeland Security (DHS). These federal agencies tackle national issues and crimes that cross state borders. State police, however, have jurisdiction to enforce laws at the statewide level and county police officers have a more localized role, which can include working at local jails.
The false statement from the choices provided is: "The United States has a national police force." This is not true because policing is primarily a local and state responsibility with multiple federal agencies assisting on a national level when necessary.