Chinese immigrants were cast as outcasts in Californian society, because of cultural differences - customs, clothing, beliefs, food, language etc -. The response to those differences caused Chinese immigrants to form their own community called Chinatowns.
Nativists thought Chinatowns were dangerous but necessary to help Chinese immigrants to assimilate, they also thought Chinatown was useful because it was used to separate immigrants from other residents.
"B is the answer because the Europeans were immune to the virus and the Indians weren't so they grew very ill which helped the Europeans."
A tariff is a tax that is placed on either imported or exported goods. It is a means of taxing foreign goods to encourage domestic industry. The answer is false.