"a free nation has the right to expect full cooperation from all groups. a free nation has the right to look to the leaders of business, of a labor, and of agriculture to take the lead in stimulating effort, not among other groups but within their own groups"

which sentence best states the main idea of this passage from roosevelt's four freedoms speech?
a- the united states vows to send money and troops to those countries that are being oppressed.
b- our hemisphere is not vulnerable to attack so we need to send money to those in danger.
c- the threat of war will soon make its way to the united states and americans must make sacrifices.
d- everyone is responsible for working together and motivating others to do the same.