Final answer:
Camp Gruber in Oklahoma functioned as an infantry training camp and also housed German prisoners of war during World War II.
Step-by-step explanation:
During World War II, Camp Gruber in Oklahoma served primarily as an infantry training camp and a prison for German soldiers. It was not a flying school for the US Air Force, a supply and maintenance depot, a bomber plant, nor any other function unrelated to infantry training and detainment of POWs; those are not historically documented functions of the camp during that period. As an infantry training camp, Camp Gruber was where many soldiers were prepared for combat before being sent overseas. The prisoners held there were mostly from North Africa, previously part of "Rommel's Army", and as a prison for German soldiers, the camp provided necessities like food and shelter under the Geneva Conventions guidelines.