Your answer is (4) influence the price of oil and set production levels
Answer: A
Explanation: Polk supported the annexation of Texas, he did not go against it.
The asnwer is A they were overcrowded and unclean
Brown v. Board of Education was a landmark case in which it was finally proven that segregation in institutions of education was highly unconstitutional, so you could say that that is the greatest effect since it made other schools become open for everyone as well.