Which of the following is a criteria for education assistance under the GI Bill?

Enrollment in an eligible program of education is a fundamental criterion for education assistance under the GI Bill because the bill is designed specifically to support veterans' pursuit of higher learning and vocational education. This means that individuals must be enrolled in programs that have been approved for GI Bill funding, which can include a wide range of educational institutions, from universities to trade schools.

This requirement ensures that the financial assistance provided under the GI Bill is directed towards programs that meet certain standards and can effectively contribute to the educational and career goals of veterans. Ensuring enrollment also helps verify that benefits are utilized for the intended purpose of gaining knowledge and skills necessary for employment or advancement in civilian life after military service.

Other factors like proof of scholarship, completion of high school, and active duty status can play roles in the broader context of education and benefits, but they do not specifically address the eligibility criteria for receiving education assistance under the GI Bill as directly as enrollment in an eligible program does.