Final answer:
None of these details about Gatsby's past are true.
Step-by-step explanation:
Gatsby's past is explored in F. Scott Fitzgerald's novel, The Great Gatsby. From the information provided, it can be concluded that none of the given options (A, B, C) are true about Gatsby's past. The novel does not mention Gatsby fighting in the war, being the son of wealthy people from the Midwest, or receiving a degree from Oxford.