50 is your correct answer
The answer is D. Isolationism was a period in Americas history when they stayed out of wars and affairs that had nothing to do with itself. Dollar is the american currency, big stick has to do with militarism, good neighbor has to do with helping neighbors and allies.
I hope this helps! :)
Political realism is the policy that your looking for
China used the one-child-policy, in which a family can only have one child
however, it has now expanded to a two-child-policy to address the issue of a growing population of males, and a smaller population of females
hope this helps