Question

immigration act of 1917 (barred zone act — prohibited immigration from most areas in asia)
immigration act of 1921 (emergency quota act — limited how many people could immigrate to the u.s from specific countries)
immigration act of 1924 (johnson-reed act — set annual immigration quotas that limited how many people could immigrate to the u.s from southern and eastern europe)
why were immigration laws like those on the list established?
to preserve american cultural identity and limit perceived threats from foreign influence
to encourage workers from asia to fill labor shortages in the u.s
to increase the number of immigrants from eastern and southern europe

Explanation:

The Immigration Act of 1917 barred immigration from most Asian areas, likely due to fears of cultural change and foreign influence. The 1921 and 1924 Acts limited immigration from specific countries (including Southern and Eastern Europe), which also aligns with a desire to preserve a certain (perceived) American cultural identity (often tied to Northern European - derived cultures at the time) and limit what were seen as threats (like job competition, cultural differences) from immigrants of different ethnic/cultural backgrounds. The options to encourage Asian workers (contradicts 1917 Act) and increase Southern/Eastern European immigration (contradicts 1924 Act) are incorrect.

Answer:

To preserve American cultural identity and limit perceived threats from foreign influence.