The Atlantic Charter is a joint declaration signed on August 14, 1941 by the President Franklin Delano Roosevelt, who intervened on behalf of the United States, and the Prime Minister of Great Britain, Winston Churchill.
The document was not a peace treaty but, as the very document states, an affirmation of "certain common principles in the national politics of our respective countries, in which the hopes of a better future for humanity lie."
The declaration also stated that countries no longer should seek the territorial aggrandizement or any other kind, and that every territorial change from that moment on had to express the will of the people, in order to maintain peace.
So, we can conclude that the correct answer is C: seeking to restore peace and self-determinism in Europe.