The correct answer is: "The Department of Homeland Security"
The Department of Homeland Security is a cabinet agency that pertains to the US goverment which is in charge of public safety. Its tasks include anti-terrorism, border controls, customs, innmigration, cyber security, disaster prevention and subsequent management, etc. It was founded after the September 11 terrorist attacks.
This agency could be compared, in terms of similar functions, to the interior ministries in other countries.