I'm not 100% sure this is the answer but I know they were successful in math.
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He took throne after his fathers death in 336 BCE, therefore the answer would be 336 BCE.
The American attitude shifted in favor of rights for Native Americans. This is based on "Polls showed that Americans believed in rights for Native Americans". Why it's not A is because it wasn't the polling that contributed to the act, but what the polls showed which is C.
1. The United States, Great Britain, Soviet Union (Roosevelt, Churchill, and Stalin)
2. D-Day
3. Soviets (Wanted land back from the Russo-Japanese War)
The president can only serve two terms in office