According to his four freedoms speech, what does roosevelt suggest will allow the world to have "freedom from fear"?
a- training people of the world to be more peaceful and less aggressive.
b- prohibiting the use of weapons during conflicts between action
c- banning the use of all weapons throughout the world
d- reducing the number of weapons available in the world

D- Reducing the number of weapons available in the world

Explanation:

In his four freedoms speech Roosevelt says:

"The fourth is freedom from fear, which, translated into world terms, means a worldwide reduction of armaments to such a point and in such a thorough fashion that no nation will be in a position to commit an act of physical aggression against any neighbor—anywhere in the world."

This means that countries should give up arms, and be allowed to conserve as many to protect themselves but not enough to do any harm into his neighbors, this way no one would be able to invade or conquer any other nation.

elon musk, ceo of spacex, a startup space company is planning to head to mars by 2023. nasa is planning to go to mars at around 2025. both are just for a basic colony.