Final answer:
The Department of Homeland Security (DHS) is the agency that would be most likely to focus on protecting the nation's borders.
Step-by-step explanation:
The type of agency that would be most likely to focus on protecting the nation's borders is the Department of Homeland Security (DHS). The DHS was created after the 9/11 attacks to centralize federal power and coordinate efforts to secure the country from threats. It oversees agencies such as the Coast Guard, Secret Service, U.S. Customs, and many other law enforcement agencies.