What type of cemetery is established by an act of Congress for the burial of veterans and their families?

The correct answer is the national cemetery. National cemeteries are established through acts of Congress specifically to provide burial spaces for veterans, their spouses, and dependent family members. These cemeteries are managed by the Department of Veterans Affairs and offer various benefits, including free burial and grave markers, signifying the nation's respect and tribute to those who have served in the military.

The option referring to a private cemetery does not align with the established purpose and governance, as private cemeteries are owned and operated by individuals or organizations and do not provide the same federal recognition or benefits for veterans.

Memorial parks usually serve as locations for commemorating individuals but do not have the specific focus on veterans and military personnel as national cemeteries do. Finally, while military graveyards may seem similar, the term is less formal and may not necessarily indicate a federal designation like national cemeteries, which specifically cater to veterans and their families with provisions set by federal law.