"Japan's Chao Qing resigned from the imperial capital, and the expedition sails circled the Penghu." Li Bai heard that his friend Chao Qingheng's shipwrecked on his way back to Japan, and he misinformed that Chao Heng had drowned, so he wrote this poem to commemorate him. It is a poem that reflects the exchanges between China and foreign countries, and reflects the exchanges with Japan during the Tang Dynasty. B is consistent with the meaning of the question.
Therefore choose B.