Answer:
Option: B. They feared Europeans were gaining too much influence and would take over their country.
Step-by-step explanation:
The Tokugawa shogunate kept Japan isolated from 1603 until 1853 because they did not want western influence in their society. Isolationism in Japan set to prevent foreign attractions threatening Japanese traditional values and society. The involvement of the British in the Opium War warned Japan to strengthen its borders and political power. The Tokugawa regime focused on social, political, and economic affairs.