The correct answer is D)Terrorism at home against U.S. citizens and institutions.
Letter A cannot be the correct answer because hyperinflation was not part of the 1980's or 1990's. America, for the most part, had great economic success during these two decades.
Letter B and C cannot be corrected because there were racial riots and protests against war throughout the 1960's.
This shows that the only correct answer can be D.