Answer:
The right answer is C. Foreigners were responsible for many of the problems in China.
Explanation:
Taking advantage of China´s social, economic and technological stagnation in the 19th century, all the major European powers, the United States and Japan had forced trade , economic and even territorial concessions - free ports such as Hong Kong or Qingdao are good examples - upon the decadent Qing dynasty. The privileges of foreigners and the dismay social and human situation of the masses enraged many in China. Those were the conditions for the start of the Boxer Rebellion.
the year that united states government stop recognizing the treaties created since the american revolution is 1871
I think it's population and transportation but I'm not sure
Economic sanctions may be comprehensive, prohibiting commercial activity with regard to an entire country, like the longstanding U.S. embargo of Cuba<span>, or they may be targeted, blocking transactions of and with particular businesses, groups, or individuals.</span>
It's definitely A as one answer, but I'm unsure about the other answer. But I can almost 100% say that C is most likely the second answer. I hope I helped in some ways!