Operation Valkyrie was the failed July 20, 1944 assassination attempt and coup plot against Hitler, led by Colonel Claus von Stauffenberg and German military officers. The plan aimed to kill Hitler and use the Valkyrie contingency plan to mobilize reserve troops to seize control of Germany. Luftwaffe was the German air force, Mein Kampf was Hitler's book, and 'None of the above' is incorrect.