I'd go with A as the answer here. A number of oaths, such as the military version, were changed to focus the idea of loyalty toward Adolf Hitler as opposed to Germany alone. In the Nazis' view and in the view of their propaganda, Hitler and Germany were one and the same.
Anti-semitism was an underpinning of Nazism, but you didn't have to be 18 to join the Hitler Youth which makes D an incompatible answer.
