Answer is B. I know for a fact!!!
Washington DC is the capital of the U.S.
The overall purpose of the conferences at Casablanca (January 1943), Tehran (November 1943), Yalta (February 1945) and Potsdam (July 1945) was to plan the Allied victory against Axis forces. The correct option among all the options that are given in the question is the third option or option "C". I hope it helps you.
