Final answer:
Considering President Roosevelt's description and the historical actions of Hitler and his regime, Hitler is best represented as an oppressor, which is reflected in his fascist, oppressive, and expansionist policies during his rule.
Step-by-step explanation:
Considering President Franklin D. Roosevelt's description of Hitler and his Nazis as pursuing an unfair 'one-way international law' that leads to oppression, Hitler represents an oppressor. This aligns with the characteristics of Hitler's regime, as it imposed totalitarian control over Germany, consolidated political power in the hands of one ruler, and engaged in warfare and genocide—especially against Jews and other minorities.
Hitler's aim to undo the Treaty of Versailles and his aggressive military campaigns underscore his role as a conqueror rather than an advocate for peace or a diplomat. His association with fascism, a dictatorial power ideology, and his actions leading to World War II highlight his oppressive intentions rather than any inclination towards peace or diplomacy. Therefore, the final answer is C) Hitler represents an oppressor.