What Was Hitler's "Final Solution

What was Hitler's "Final Solution"?

A) another name for the blitzkrieg, a military strategy Hitler primarily employed at the end of the war
B) a last-minute alliance between the Nazis and the Japanese to maintain control of the Pacific
C) the military tactic of liberating the most important islands in the Pacific and bypassing others
D) the wholesale extermination of the Jews, who Hitler blamed for most of Germany's problems
E) his decision to force all Jews to join the German military because so few Nazi soldiers were left