what triggered chinas 1990-1901 boxer rebellion?

a. a prolonged famine that had killed thousands of chinese
b. the presence of westerns
c. the imprisonment of university professors
d. the government's massacre of a vilages peasants

b. the presence of westerns

The Boxer Rebellion was largely triggered by anti-foreign and anti-Christian sentiments among the Chinese population, who were angered by the presence and influence of Western powers in China.