The correct answer is D) Japan became even more isolationist than it had been.
After the Mongol’s invasions, the foreign policy of Japan to Korea and China was isolation. Japan became even more isolationist than it had been.
The Japanese relations with China in the 9th century ended with the problems with Tang China. After the two invasions of Mongol’s, victorious Japan was not interest in establishing communication with China or Korea. Japan decided on an isolationist policy against the two invaders.
