Final answer:
The GI Bill would be the most helpful for Aaron to attend college as an engineering student after his military service.
Step-by-step explanation:
Aaron, having just returned from serving in the U.S. Army, would benefit most from the GI Bill, which is formally known as The Serviceman's Readjustment Act of 1944. This act was established to provide federal assistance to veterans in several areas including education.
Under this bill, veterans could receive funds to cover tuition, books, supplies, and living expenses if they chose to return to school or attend college. The GI Bill was significant in aiding nearly eight million former servicemen in furthering their education, which in turn led to a substantial increase in the number of college degrees awarded in the years following World War II.