The answer is D. Nixon resigned
“Society was liberalized, and Gorbachev sought détente with the USA so as to be able to transfer funding from defense to civil society. He declared that he would not support Communist regimes in other countries if their peoples were opposed to them. He thus started a chain reaction which led to the fall of communism in Europe.”
Horrible, selfish and untrustworthy.
The Iraq War did not end quickly because the U.S. Government specifically the State and Defense Departments did not have a clear exit strategy. Following civil unrest in Iraq as well as increasing attacks on U.S. soldiers and the newly formed Iraqi Government the U.S. Government was unable to withdraw quickly and suffered large casualties and expended hundreds of billions of dollars in resources.