Answer: British Empire
Step-by-step explanation:
During the period of China's Open Door Policy where they could not resist the major powers at the time due to their military weakness, the major powers took advantage to make China give them equal rights to Chinese trade.
The period lasted from roughly 1899 till 1949 when the Communists came to complete power and ended such practices.
The British during this period controlled much of the Yangtze River as they had done since the mid 19th century when they defeated China in the First Opium war.