Great archipelago Indonesia,
Islam spread to Mali mainly through trade with Arab traders.
Explanation:
A. A constitutional amendment lowered the number of immigrants allowed.
B. Fake sciences claimed that whites were smarter and more capable than other races.
C. More whites and nonwhites married and had families.
D. Nativists worked to help the immigrants become citizens faster.
This sentence technically doesn't contain an error in verb-noun agreement, however the noun "each one" is odd here. It should be "everyone"