At the end of the 1800s, why was the United States unable to expand trade with China?

In the late 1800s, several imperialist powers held spheres of influence and special trading privileges in China, limiting other countries’ access. The United States feared being shut out and later promoted the Open Door Policy to protect equal trade opportunities. Japan did not control most of China or simply block U.S. ships, so A is the best choice.

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