your answer is
relations between the soviet union and the united states were driven by a complex interplay of ideological, political, and economic factors, which led to shifts between cautious cooperation and often bitter superpower rivalry over the years. the distinct differences in the political systems of the two countries often prevented them from reaching a mutual understanding on key policy issues and even, as in the case of the cuban missile crisis, brought them to the brink of war.
the united states government was initially hostile to the soviet leaders for taking russia out of world war i and was opposed to a state ideologically based on communism. although the united states embarked on a famine relief program in the soviet union in the early 1920s and american businessmen established commercial ties there during the period of the new economic policy (1921–29), the two countries did not establish diplomatic relations until 1933. by that time, the totalitarian nature of joseph stalin's regime presented an insurmountable obstacle to friendly relations with the west. although world war ii brought the two countries into alliance, based on the common aim of defeating nazi germany, the soviet union's aggressive, antidemocratic policy toward eastern europe had created tensions even before the war ended.
your answer would be (b)
the ottoman empire
the christian crusades: conquered constantinople in 1453 ce
alexius sultan of the ottoman empire
fall of avars by ottomans ended byzantine empire
the ottomans made islammic the primary religion in the region, replacing orthodox christianity. they did allow the practice of christianity
the second industrial revolution occurred in the u.s. beginning in the and its colonial empire allowed its many technological innovations to spread although the american industrial revolution wouldn't take full effect