1. potetial presidential candidates form exploratary committees

2. ?

3. candidates for each party compete in general elections

a. national conventions are held to select candidates for the primary elections

b. members of the electoral college formally select the president of the united states

c. the senate approves a list of candidates for each party's presidential nomination

d. parties select their presidential candidates through primaries and caucuses

B. members of the electoral college formally select the president of the United States will be your answer.

the mongolian invasion of china and central asia resulted in a disruption of the silk road as the chinese garrisons lost support from the chinese kingdoms which fell under the mongols. however, as the mongols established a formal dynasty in china, the successors of genghis khan restored the garrisons along the silk road allowing the safe travel caravans again.