Why did the Shogunate's close Japan's ports and ban foreign trades

A. They did not like the goods Europeans were trading
B. They did not want to share the secrets of the samurai
C. They feared Europeans would try to take control of Japan
D. They feared Europeans would bring Kabuki back to Europe
I think it's C but I'm not sure

I'm not taking world studies but frankly, A, B, and D sound stupid, As a 2nd opinion.