This was Nazi Germany's plan during World War II to systematically exterminate the Jewish population in Nazi-occupied Europe through genocide. This policy was formulated in procedural terms at the Wannsee Conference in January 1942, and culminated in the Holocaust which saw the killing of two thirds of the Jewish population of Europe.

The Final Solution was the name of the plan.

The Allies knew of the final solution through intel, but thought it was a military plan, not plans for the Holocaust.

Solution is a noun and final is an adjective and the Final Solution is a noun phrase or, arguably, a proper noun.

the name foe nazi germanys plan for the systamatic killing of eurpoean jews

Children were treated good in the final solution