A) D) & E) The transcontinental railroad needs more historical credit
Answer: While c. 476 CE is the traditionally accepted date for the end of the Western Roman Empire, that entity did continue on under the rule of Odoacer (r. 476-493 CE) who, officially anyway, was simply ruling in place of the deposed emperor Julius Nepos (who had been deposed by the general Orestes who had placed his son, Romulus Augustulus, on the throne).
Explanation:
People were governed by councils, instead of by an absolute ruler
The official introduction, according to the Japanese records actually happens in 552 CE when monks from Korea, this time, came to Japan and introduced the principals precepts of Buddhism and brought some treasures with them.
The first years were not actually easy as Buddhism became one more tool in the struggle for power over the imperial dynasty by the Soga clan over the rival Mononobe and Nakatoni clans.