Which agency within the DOJ is tasked with overseeing immigration laws?

The correct choice is Immigration and Customs Enforcement (ICE), as it is the agency within the Department of Justice that specifically focuses on enforcing immigration laws as well as customs regulations. ICE is responsible for investigating and enforcing laws related to immigration and customs, which includes the apprehension and deportation of individuals who are in the U.S. illegally.

In addition to immigration, ICE also plays a critical role in addressing human trafficking and other crimes related to borders and customs violations. This dual focus on immigration and customs distinguishes ICE from other agencies, reflecting its comprehensive mandate in managing issues related to the flow of individuals and goods across U.S. borders.

The other agencies mentioned, such as the U.S. Marshals Service, ATF, and the Federal Bureau of Prisons, have different areas of jurisdiction and responsibilities. The U.S. Marshals Service deals primarily with fugitive apprehension and federal law enforcement; the ATF focuses on matters related to alcohol, tobacco, firearms, and explosives; and the Federal Bureau of Prisons manages the incarceration of federal offenders. Therefore, their missions do not encompass the supervision or enforcement of immigration laws, making them less relevant to the question at hand.