When are empires considered to have collapsed?

Societal collapse (also known as civilizational collapse) is the fall of a complex human society characterized by the loss of cultural identity and of socioeconomic complexity, the downfall of government, and the rise of violence.[1] Possible causes of a societal collapse include natural catastrophe, war, pestilence, famine, and depopulation. A collapsed society may revert to a more primitive state, be absorbed into a stronger society, or completely disappear.

Explanation:

Often times, the biggest reason for the decline of an empire is that they have become overextended; either by reaching too far, too fast or by being forced, often times through economic need, to keep on capturing land.

Explanation:

the answer would be a).

angel island immigration station was an immigration station located in san francisco bay which worked from 1910 to 1940. the majority of immigrants that got there were from the asian hemisphere, specifically from china, japan, russia, and south asia, being china the country from where more people arrived.

the number of foreigners arriving at it took the attention of americans who feared the new arrivals would take their jobs. the work opportunities were not abundant due to the economic comedown of 1870 and the asians, as newcomers, were willing to work for cheaper wages. soon they started to be seen as a threat, which led to an increased discrimination against the chinese - the biggest ethnicity arrived at this station until 1915 when japanese immigrants outnumbered them - being considered as unsuitable americans hence their looks and social situation.

at the station, the immigrant's detention may vary depending on how long the interrogation process took: it could be weeks, months, or even years.

finally, in 1940 an explosion destroyed administration building located on the island, so the united states government decided to stop the process.