The correct answer is - B. The Mongolian conquest of Persia ended a golden age, which was a peak period of Islamic literature, philosophy, medicine, and art.
The Mongols conquered Persia and destroyed lot of cities, killed lot of people, and put end to the Islamic Caliphates, though it has to be said that the Mongols were actually provoked, and initially were not the ones that were seeking war.
By conquering the region, the Mongols put an end to the so called Islamic Golden Age, when the Islamic literature, philosophy, art, medicine, culture as a whole, was at its peak. Unfortunately, even after the Mongols left, the Muslim countries never got back to their glorious and forward thinking ways, and the reason for that is that some of the most influential Islamic scholars declared the math as a work of the devil, which pretty much cut all further development in the Middle Ages, and still has big negative effects in the present.
An invasion by goths subsided enabling him to devote attention in the reconstruction of Rome.<span />
The Cold War really began before WW II as the US and Russia had 2 very opposing views of government and didn't trust each other. However, during the war, the two countries had to put their differences aside to beat Nazi Germany. Towards the end of the war, it was evident that heat was building up between the two countries again. The Soviets were taking liberties in areas that suggested they were not only interested in winning the war but taking land also. They insisted they control Berlin at the end of the war, wanted Manchuria for their own and not to give back to China, insisted they be in charge of Postwar Japan operations (MacArthur said absolutely not) and were really upset that the US had the power to use a nuclear bomb that they didn't even know existed. The Soviets were also aggressive after the war in areas such as Korea and Viet Nam with "support".
President Richard Nixon supported the policy of détente as a way to reduce tensions between the United States and the Soviet Union
