Which federal agency oversees the administration of veterans' benefits?

The U.S. Department of Veterans Affairs (VA) is the federal agency specifically tasked with overseeing the administration of veterans' benefits. This includes a broad range of services and support for veterans, such as healthcare, disability compensation, education benefits, and housing assistance. The VA was established to ensure that those who have served in the military receive the necessary care and benefits they have earned through their service.

The other federal agencies mentioned have distinct roles that do not primarily focus on veterans’ benefits. The Department of Defense (DoD) is responsible for military operations and the security of the country, while the Social Security Administration (SSA) manages social security programs, including retirement and disability benefits, but does not administer veterans' benefits. The Department of Homeland Security (DHS) focuses on national security and emergency management, further diverging from the veteran-centric responsibilities of the VA. Thus, the VA stands out as the designated agency for veterans’ matters, making it the correct answer.