Question

read the two excerpts from roosevelts \four freedoms\ speech.
i have called for personal sacrifice. i am assured of the willingness of almost all americans to respond to that call.
...
this nation has placed its destiny in the hands and heads and hearts of its millions of free men and women; and its faith in freedom under the guidance of god. freedom means the supremacy of human rights everywhere. our support goes to those who struggle to gain those rights or keep them. our strength is our unity of purpose. to that high concept there can be no end save victory.
the second excerpt supports the earlier claim that \personal sacrifice is necessary\ by concluding that
national support for the war will lead to victory.
americans have always fought for democracy.
one day everyone in the world will enjoy freedom.
all americans will be willing to make sacrifices.

Explanation:

The first excerpt mentions the call for personal sacrifice and the willingness of almost all Americans to respond. The second excerpt emphasizes the nation's unity of purpose (which is related to the support as a form of sacrifice - contributing to the common goal). National support (as a form of sacrifice - giving time, resources etc. for the war effort) leading to victory ties in with the idea that personal sacrifice (in the form of national support) is necessary. The other options:

• “Americans have always fought for democracy” - the text doesn't focus on the history of fighting for democracy in the context of proving the “personal sacrifice is necessary” claim.
• “one day everyone in the world will enjoy freedom” - is more of a future - oriented statement about freedom's reach, not about sacrifice.
• “all Americans will be willing to make sacrifices” - the first excerpt says “almost all”, so this is an over - statement.

Answer:

national support for the war will lead to victory.