The correct answer is B. Interactions between the Chinese and Westerners were limited, and only one port was open for trade.
Step-by-step explanation
China's closed-door policy is the name given to China's international policy before the 19th century, which focused on growing the Chinese economy internally, limiting relations with other nations. From the previous century, Chinese products were widely desired by Europeans, however, they were very difficult to obtain due to the extensive merchant routes Europeans had to travel, the long shipping route to reach the only functioning port for Europeans and the high risk that this meant for them. Furthermore, Chinese merchants were not allowed to exchange their products for products from Europe, they only could exchange their products for money. This relationship remained closed until the beginning of the 19th century when the opium form Europe trade reached China and caused a crisis due to the addiction to this plant. So, the correct answer is B. Interactions between the Chinese and Westerners were limited, and only one port was open for trade.